CVE-2023-48795
published 2023-12-18CVE-2023-48795: The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks…
PriorityP184medium5.9CVSS 3.1
AVNACHPRNUINSUCNIHAN
ITWEXPLOITVulnCheck KEV
Exploited in the wild
EPSS
93.31%
99.8th percentile
The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against SSH's use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in [email protected] and (if CBC is used) the [email protected] MAC algorithms. This also affects Maverick Synergy Java SSH API before 3.1.0-SNAPSHOT, Dropbear through 2022.83, Ssh before 5.1.1 in Erlang/OTP, PuTTY before 0.80, AsyncSSH before 2.14.2, golang.org/x/crypto before 0.17.0, libssh before 0.10.6, libssh2 through 1.11.0, Thorn Tech SFTP Gateway before 3.4.6, Tera Term before 5.1, Paramiko before 3.4.0, jsch before 0.2.15, SFTPGo before 2.5.6, Netgate pfSense Plus through 23.09.1, Netgate pfSense CE through 2.7.2, HPN-SSH through 18.2.0, ProFTPD before 1.3.8b (and before 1.3.9rc2), ORYX CycloneSSH before 2.3.4, NetSarang XShell 7 before Build 0144, CrushFTP before 10.6.0, ConnectBot SSH library before 2.2.22, Apache MINA sshd through 2.11.0, sshj through 0.37.0, TinySSH through 20230101, trilead-ssh2 6401, LANCOM LCOS and LANconfig, FileZilla before 3.66.4, Nova before 11.8, PKIX-SSH before 14.4, SecureCRT before 9.4.3, Transmit5 before 5.10.4, Win32-OpenSSH before 9.5.0.0p1-Beta, WinSCP before 6.2.2, Bitvise SSH Server before 9.32, Bitvise SSH Client before 9.33, KiTTY through 0.76.1.13, the net-ssh gem 7.2.0 for Ruby, the mscdex ssh2 module before 1.15.0 for Node.js, the thrussh library before 0.35.1 for Rust, and the Russh crate before 0.40.2 for Rust.
Affected
177 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| 9bis | kitty | <= 0.76.1.13 | — |
| apache | mina_sshd | <= 2.11.0 | — |
| apache | sshd | <= 2.11.0 | — |
| apache | sshj | <= 0.37.0 | — |
| apache_software_foundation | apache_mina_sshd | <= 2.11.0 | — |
| apple | macos | >= 14.0 < 14.4 | 14.4 |
| apple | macos_sonoma | — | — |
| asyncssh_project | asyncssh | < 2.14.2 | 2.14.2 |
| bitvise | ssh_client | < 9.33 | 9.33 |
| bitvise | ssh_server | < 9.32 | 9.32 |
| connectbot | sshlib | < 2.2.22 | 2.2.22 |
| crates | thrussh | < 0.35.1 | 0.35.1 |
| crushftp | crushftp | < 10.6.0 | 10.6.0 |
| crushftp | crushftp | <= 10.6.0 | — |
| debian | debian_linux | — | — |
| debian | dropbear | < dropbear 2022.83-1+deb12u1 (bookworm) | dropbear 2022.83-1+deb12u1 (bookworm) |
| debian | erlang | < dropbear 2022.83-1+deb12u1 (bookworm) | dropbear 2022.83-1+deb12u1 (bookworm) |
| debian | filezilla | < dropbear 2022.83-1+deb12u1 (bookworm) | dropbear 2022.83-1+deb12u1 (bookworm) |
| debian | golang-go.crypto | < dropbear 2022.83-1+deb12u1 (bookworm) | dropbear 2022.83-1+deb12u1 (bookworm) |
| debian | jsch | < dropbear 2022.83-1+deb12u1 (bookworm) | dropbear 2022.83-1+deb12u1 (bookworm) |
| debian | libmina-sshd-java | — | — |
| debian | libssh | < dropbear 2022.83-1+deb12u1 (bookworm) | dropbear 2022.83-1+deb12u1 (bookworm) |
| debian | libssh2 | < dropbear 2022.83-1+deb12u1 (bookworm) | dropbear 2022.83-1+deb12u1 (bookworm) |
| debian | openssh | < dropbear 2022.83-1+deb12u1 (bookworm) | dropbear 2022.83-1+deb12u1 (bookworm) |
| debian | paramiko | < dropbear 2022.83-1+deb12u1 (bookworm) | dropbear 2022.83-1+deb12u1 (bookworm) |
Detection & IOCsextracted from sources · hover to see the quote
- →Monitor for unexpected SSH connection failures or resets, particularly after the initial handshake, which may indicate an active Terrapin attack. ↗
- →Monitor network traffic for unusual packet injections during the SSH negotiation/handshake phase. ↗
- →Watch system logs for failures to negotiate EXT_INFO or sudden downgrades in cipher suite strength during SSH sessions. ↗
- →The attack requires the connection to be secured by ChaCha20-Poly1305 or CBC with Encrypt-then-MAC; detect or alert on SSH sessions negotiating these cipher modes on unpatched systems. ↗
- →The attack manipulates SSH sequence numbers during the handshake to truncate SSH_MSG_EXT_INFO; detection logic should look for desynchronized sequence numbers between client and server during key exchange. ↗
- →Identify vulnerable OpenSSH instances using the Qualys CSAM asset query for unauthorized TCP port 22 exposure. ↗
- ·The Terrapin attack requires the attacker to be in an adversary-in-the-middle (MiTM) position at the network layer; without this position, exploitation is not possible. ↗
- ·The strict key exchange countermeasure (the primary fix) is only effective when implemented on BOTH the client and the server side. ↗
- ·Apache MINA SSHD mitigations require both client and server to be updated to version 2.12.0 or later; a one-sided patch is insufficient. ↗
- ·If patching is not immediately possible, disable ChaCha20-Poly1305 and CBC-mode ciphers and prioritize AES-GCM to remove the conditions required for the attack. ↗
- ·Scans show approximately 77% adoption of the vulnerable encryption modes (ChaCha20-Poly1305 or CBC with Encrypt-then-MAC), making the attack broadly feasible in real-world scenarios. ↗
CVSS provenance
nvdv3.15.9MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
ghsa5.9MEDIUM
osv9.8CRITICAL
vulncheck5.9MEDIUM
vendor_ubuntu9.8CRITICAL
vendor_debian5.9LOW
vendor_msrc5.9MEDIUM
vendor_oracle5.9MEDIUM
vendor_redhat5.9MEDIUM
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CISA ICS
Siemens SIMATIC S7-1500 CPU Family
cisa_ics·2025-06-12
Siemens SIMATIC S7-1500 CPU Family
ICS Advisory
##
Siemens SIMATIC S7-1500 CPU Family
Release DateJune 12, 2025
Alert CodeICSA-25-162-05
Related topics:
Industrial Control System Vulnerabilities, Industrial Control Systems
As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global).
View CSAF
## 1. EXECUTIVE SUMMARY
- CVSS v4 8.7
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Siemens
- Equipment: SIMATIC S7-1500 CPU family
- Vulnerabilities: Missing Encryption of Sensitive Data, Out-of-bounds Read, Use After Free, Stack-
Oracle
Oracle Oracle Retail Applications Risk Matrix: Xenvironment (Apache Mina SSHD) — CVE-2023-48795
vendor_oracle·2025-04-15·CVSS 5.9
CVE-2023-48795 [MEDIUM] Oracle Oracle Retail Applications Risk Matrix: Xenvironment (Apache Mina SSHD) — CVE-2023-48795
Oracle Oracle Retail Applications Risk Matrix: Xenvironment (Apache Mina SSHD) vulnerability
CVE: CVE-2023-48795
CVSS: 5.9
Protocol: HTTP
Remote exploit: Yes
Affected versions: Network
Advisory: cpuapr2025 (APR 2025)
CISA ICS
ABB M2M Gateway
cisa_ics·2025-04-15
ABB M2M Gateway
ICS Advisory
##
ABB M2M Gateway
Release DateApril 15, 2025
Alert CodeICSA-25-105-08
Related topics:
Industrial Control System Vulnerabilities, Industrial Control Systems
View CSAF
## 1. EXECUTIVE SUMMARY
- CVSS v4 8.8
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: ABB
- Equipment: M2M Gateway
- Vulnerabilities: Integer Overflow or Wraparound, Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling'), Unquoted Search Path or Element, Untrusted Search Path, Use After Free, Out-of-bounds Write, Buffer Copy without Checking Size of Input ('Classic Buffer Overflow'), Missing Release of Memory after Effective Lifetime, Allocation of Resources Without Limits or Throttling, Improper Privilege Management, Improper Limitati
Ubuntu
Dropbear vulnerabilities
vendor_ubuntu·2025-02-25·CVSS 7.5
CVE-2021-36369 [HIGH] Dropbear vulnerabilities
Title: Dropbear vulnerabilities
Summary: Several security issues were fixed in dropbear.
Manfred Kaiser discovered that Dropbear through 2020.81 does not properly
check the available authentication methods in the client-side SSH code.
An attacker could use this vulnerability to gain unauthorized access to
remote systems. (CVE-2021-36369)
Fabian Bäumer, Marcus Brinkmann, and Jörg Schwenk discovered that the SSH
transport protocol implementation in Dropbear had weak integrity checks.
An attacker could use this vulnerability to bypass security features
like encryption and integrity checks. (CVE-2023-48795)
Instructions: In general, a standard system update will make all the necessary changes.
Ubuntu
ProFTPD vulnerabilities
vendor_ubuntu·2025-02-25·CVSS 5.9
CVE-2023-48795 [MEDIUM] ProFTPD vulnerabilities
Title: ProFTPD vulnerabilities
Summary: Several security issues were fixed in proftpd-dfsg.
Fabian Bäumer, Marcus Brinkmann, and Jörg Schwenk discovered that the
transport protocol implementation in ProFTPD had weak integrity checks.
An attacker could use this vulnerability to bypass security features
like encryption and integrity checks. (CVE-2023-48795)
Martin Mirchev discovered that ProFTPD did not properly validate user
input over the network. An attacker could use this vulnerability to
crash ProFTPD or execute arbitrary code. (CVE-2023-51713)
Brian Ristuccia discovered that ProFTPD incorrectly inherited groups
from the parent process. An attacker could use this vulnerability to
elevate privileges. (CVE-2024-48651)
Instructions: In general, a standard system update will make all t
CISA ICS
Siemens SCALANCE W700
cisa_ics·2025-02-13
Siemens SCALANCE W700
ICS Advisory
##
Siemens SCALANCE W700
Release DateFebruary 13, 2025
Alert CodeICSA-25-044-09
Related topics:
Industrial Control System Vulnerabilities, Industrial Control Systems
As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global).
View CSAF
## 1. EXECUTIVE SUMMARY
- CVSS v3 9.8
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Siemens
- Equipment: SCALANCE W700
- Vulnerabilities: Double Free, Improper Restriction of Communication Channel to Intended Endpoints, Improper Resource Sh
Oracle
Oracle Oracle Database Server Risk Matrix: Database Migration Assistant for Unicode (Apache Mina SSHD) — CVE-2023-48795
vendor_oracle·2025-01-15·CVSS 5.9
CVE-2023-48795 [MEDIUM] Oracle Oracle Database Server Risk Matrix: Database Migration Assistant for Unicode (Apache Mina SSHD) — CVE-2023-48795
Oracle Oracle Database Server Risk Matrix: Database Migration Assistant for Unicode (Apache Mina SSHD) vulnerability
CVE: CVE-2023-48795
CVSS: 5.9
Protocol: SSH
Remote exploit: Yes
Affected versions: Network
Advisory: cpujan2025 (JAN 2025)
CISA ICS
Siemens SINEC INS
cisa_ics·2024-11-14
Siemens SINEC INS
ICS Advisory
##
Siemens SINEC INS
Release DateNovember 14, 2024
Alert CodeICSA-24-319-08
Related topics:
Industrial Control System Vulnerabilities, Industrial Control Systems
As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global).
View CSAF
## 1. EXECUTIVE SUMMARY
- CVSS v3 9.9
- ATTENTION: Exploitable remotely/low attack complexity/public exploits are available/known public exploitation
- Vendor: Siemens
- Equipment: SINEC INS
- Vulnerabilities: Improper Authentication, Out-of-bounds Write, Ineffici
Oracle
Oracle Oracle Blockchain Platform Risk Matrix: Blockchain Cloud Service Console (OpenSSH) — CVE-2023-48795
vendor_oracle·2024-10-15·CVSS 5.9
CVE-2023-48795 [MEDIUM] Oracle Oracle Blockchain Platform Risk Matrix: Blockchain Cloud Service Console (OpenSSH) — CVE-2023-48795
Oracle Oracle Blockchain Platform Risk Matrix: Blockchain Cloud Service Console (OpenSSH) vulnerability
CVE: CVE-2023-48795
CVSS: 5.9
Protocol: SSH
Remote exploit: Yes
Affected versions: Network
Advisory: cpuoct2024 (OCT 2024)
Ubuntu
AsyncSSH vulnerability
vendor_ubuntu·2024-10-02
CVE-2023-48795 AsyncSSH vulnerability
Title: AsyncSSH vulnerability
Summary: A protocol flaw was fixed in AsyncSSH.
Fabian Bäumer, Marcus Brinkmann, Jörg Schwenk discovered that the SSH
protocol was vulnerable to a prefix truncation attack. If a remote attacker
was able to intercept SSH communications, extension negotiation messages
could be truncated, possibly leading to certain algorithms and features
being downgraded. This issue is known as the Terrapin attack. This update
adds protocol extensions to mitigate this issue.
Instructions: In general, a standard system update will make all the necessary changes.
Red Hat
mina-sshd: integrity check bypass vulnerability
vendor_redhat·2024-08-12·CVSS 5.9
CVE-2024-41909 [MEDIUM] CWE-354 mina-sshd: integrity check bypass vulnerability
mina-sshd: integrity check bypass vulnerability
Like many other SSH implementations, Apache MINA SSHD suffered from the issue that is more widely known as CVE-2023-48795. An attacker that can intercept traffic between client and server could drop certain packets from the stream, potentially causing client and server to consequently end up with a connection for which
some security features have been downgraded or disabled, aka a Terrapin
attack
The mitigations to prevent this type of attack were implemented in Apache MINA SSHD 2.12.0, both client and server side. Users are recommended to upgrade to at least this version. Note that both the client and the server implementation must have mitigations applied against this issue, otherwise the connection may still be affected.
A flaw was found
Oracle
Oracle Oracle GoldenGate Risk Matrix: General (Apache Mina SSHD) — CVE-2023-48795
vendor_oracle·2024-07-15·CVSS 5.9
CVE-2023-48795 [MEDIUM] Oracle Oracle GoldenGate Risk Matrix: General (Apache Mina SSHD) — CVE-2023-48795
Oracle Oracle GoldenGate Risk Matrix: General (Apache Mina SSHD) vulnerability
CVE: CVE-2023-48795
CVSS: 5.9
Protocol: SSH
Remote exploit: Yes
Affected versions: Network
Advisory: cpujul2024 (JUL 2024)
CISA ICS
Siemens RUGGEDCOM APE 1808
cisa_ics·2024-07-11·CVSS 5.9
[MEDIUM] Siemens RUGGEDCOM APE 1808
ICS Advisory
##
Siemens RUGGEDCOM APE 1808
Release DateJuly 11, 2024
Alert CodeICSA-24-193-11
Related topics:
Industrial Control System Vulnerabilities, Industrial Control Systems
As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global).
View CSAF
## 1. EXECUTIVE SUMMARY
- CVSS v4 8.2
- ATTENTION: Exploitable remotely
- Vendor: Siemens
- Equipment: RUGGEDCOM APE1808
- Vulnerability: Truncation of Security-relevant Information
## 2. RISK EVALUATION
Successful exploitation of this vulnerability could a
Ubuntu
LXD vulnerability
vendor_ubuntu·2024-04-22
CVE-2023-48795 LXD vulnerability
Title: LXD vulnerability
Summary: LXD could be made to bypass integrity checks if it received specially crafted
input.
Fabian Bäumer, Marcus Brinkmann, and Jörg Schwenk discovered that LXD
incorrectly handled the handshake phase and the use of sequence numbers in SSH
Binary Packet Protocol (BPP). If a user or an automated system were tricked
into opening a specially crafted input file, a remote attacker could possibly
use this issue to bypass integrity checks.
Instructions: In general, a standard system update will make all the necessary changes.
Jenkins
Jenkins Security Advisory 2024-04-17
vendor_jenkins·2024-04-17·CVSS 5.9
CVE-2023-48795 [MEDIUM] Jenkins Security Advisory 2024-04-17
Title: Jenkins Security Advisory 2024-04-17
Jenkins Security Advisory 2024-04-17
Jenkins Security Home
For Administrators
Overview
Terminology
Vulnerabilities and Scoring
Security Advisories
Security Issues
Advisory Schedule
Vulnerabilities in Plugins
How We Fix Security Issues
For Reporters
Reporting Vulnerabilities
Jenkins CNA
For Maintainers
Overview
Vulnerabilities in Plugins
Jenkins Security Team
About
Contributions
This advisory announces vulnerabilities in the following Jenkins deliverables:
Jenkins (core)
Descriptions
Terrapin SSH vulnerability in Jenkins CLI client
SECURITY-3386
/
CVE-2023-48795
Severity (CVSS):
Medium
Description:
The CLI client ( jenkins-cli.jar
Oracle
Oracle Oracle Database Server Risk Matrix: Grid Infrastructure (Apache Mina SSHD) — CVE-2023-48795
vendor_oracle·2024-04-15·CVSS 5.9
CVE-2023-48795 [MEDIUM] Oracle Oracle Database Server Risk Matrix: Grid Infrastructure (Apache Mina SSHD) — CVE-2023-48795
Oracle Oracle Database Server Risk Matrix: Grid Infrastructure (Apache Mina SSHD) vulnerability
CVE: CVE-2023-48795
CVSS: 5.9
Protocol: SSH
Remote exploit: Yes
Affected versions: Network
Advisory: cpuapr2024 (APR 2024)
CISA ICS
Siemens RUGGEDCOM APE1808
cisa_ics·2024-04-11·CVSS 7.5
[HIGH] Siemens RUGGEDCOM APE1808
ICS Advisory
##
Siemens RUGGEDCOM APE1808
Release DateApril 11, 2024
Alert CodeICSA-24-102-04
As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global).
View CSAF
## 1. EXECUTIVE SUMMARY
- CVSS v4 8.2
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Siemens
- Equipment: RUGGEDCOM APE1808
- Vulnerabilities: Cross-site Scripting, Improper Privilege Management, Improper Check for Unusual or Exceptional Conditions, Truncation of Security-relevant Information, Insufficient Session Expiration
#
Apple
CVE-2023-48795: macOS Sonoma 14.4
vendor_apple·2024-03-07·CVSS 5.9
CVE-2023-48795 [MEDIUM] CVE-2023-48795: macOS Sonoma 14.4
Apple Security Update: About the security content of macOS Sonoma 14.4
Product: macOS Sonoma
Version: 14.4
CVE: CVE-2023-48795
Component: CVE-2023-48795
Jenkins
Jenkins Security Advisory 2024-03-06
vendor_jenkins·2024-03-06·CVSS 5.9
CVE-2023-48795 [MEDIUM] Jenkins Security Advisory 2024-03-06
Title: Jenkins Security Advisory 2024-03-06
Jenkins Security Advisory 2024-03-06
Jenkins Security Home
For Administrators
Overview
Terminology
Vulnerabilities and Scoring
Security Advisories
Security Issues
Advisory Schedule
Vulnerabilities in Plugins
How We Fix Security Issues
For Reporters
Reporting Vulnerabilities
Jenkins CNA
For Maintainers
Overview
Vulnerabilities in Plugins
Jenkins Security Team
About
Contributions
This advisory announces vulnerabilities in the following Jenkins deliverables:
AppSpider
Plugin
Bitbucket Branch Source
Plugin
Build Monitor View
Plugin
Delphix
Plugin
Delphix
Plugin
docker-build-step
Plugin
GitBucket
Plugin
HTML Publisher
Ubuntu
Paramiko vulnerability
vendor_ubuntu·2024-01-25
CVE-2023-48795 Paramiko vulnerability
Title: Paramiko vulnerability
Summary: A protocol flaw was fixed in Paramiko.
Fabian Bäumer, Marcus Brinkmann, Jörg Schwenk discovered that the SSH
protocol was vulnerable to a prefix truncation attack. If a remote attacker
was able to intercept SSH communications, extension negotiation messages
could be truncated, possibly leading to certain algorithms and features
being downgraded. This issue is known as the Terrapin attack. This update
adds protocol extensions to mitigate this issue.
Instructions: In general, a standard system update will make all the necessary changes.
Ubuntu
FileZilla vulnerability
vendor_ubuntu·2024-01-18
CVE-2023-48795 FileZilla vulnerability
Title: FileZilla vulnerability
Summary: FileZilla could be made to expose sensitive information over the
network.
Fabian Baeumer, Marcus Brinkmann and Joerg Schwenk discovered that the SSH
protocol used in FileZilla is prone to a prefix truncation attack, known as
the "Terrapin attack". A remote attacker could use this issue to downgrade or
disable some security features and obtain sensitive information.
Instructions: In general, a standard system update will make all the necessary changes.
Ubuntu
libssh2 vulnerability
vendor_ubuntu·2024-01-15
CVE-2023-48795 libssh2 vulnerability
Title: libssh2 vulnerability
Summary: libssh2 could be made to expose sensitive information over the network.
Fabian Bäumer, Marcus Brinkmann, Jörg Schwenk discovered that the SSH
protocol was vulnerable to a prefix truncation attack. If a remote attacker
was able to intercept SSH communications, extension negotiation messages
could be truncated, possibly leading to certain algorithms and features
being downgraded. This issue is known as the Terrapin attack. This update
adds protocol extensions to mitigate this issue.
Instructions: In general, a standard system update will make all the necessary changes.
Ubuntu
OpenSSH vulnerabilities
vendor_ubuntu·2024-01-11·CVSS 5.9
CVE-2023-48795 [MEDIUM] OpenSSH vulnerabilities
Title: OpenSSH vulnerabilities
Summary: Several security issues were fixed in OpenSSH.
USN-6560-1 fixed several vulnerabilities in OpenSSH. This update provides
the corresponding update for Ubuntu 16.04 LTS and Ubuntu 18.04 LTS.
Original advisory details:
Fabian Bäumer, Marcus Brinkmann, Jörg Schwenk discovered that the SSH
protocol was vulnerable to a prefix truncation attack. If a remote attacker
was able to intercept SSH communications, extension negotiation messages
could be truncated, possibly leading to certain algorithms and features
being downgraded. This issue is known as the Terrapin attack. This update
adds protocol extensions to mitigate this issue. (CVE-2023-48795)
It was discovered that OpenSSH incorrectly handled user names or host names
with shell metacharacters. An at
Palo Alto
Impact of Terrapin SSH Attack
vendor_paloalto·2024-01-09·CVSS 5.9
CVE-2023-48795 [MEDIUM] CWE-354 Impact of Terrapin SSH Attack
Impact of Terrapin SSH Attack
The Terrapin attack allows an attacker with the ability to intercept SSH traffic on affected Palo Alto Networks products (through machine-in-the-middle or MitM attacks) to downgrade connection security and force the usage of less secure client authentication algorithms when an administrator or user connects to the product.
This issue does not impact the SSH server component of PAN-OS software configured to exclusively use strong cipher algorithms or configured to operate in FIPS-CC mode, which removes support for the impacted algorithms.
When using the PAN-OS SSH client to connect to an SSH server that supports the CHACHA20-POLY1305 algorithm or any Encrypt-then-MAC algorithms, the traffic is susceptible to this attack.
This issue affects Prisma SD-WAN ION
Debian
CVE-2024-41909: libmina-sshd-java - Like many other SSH implementations, Apache MINA SSHD suffered from the issue th...
vendor_debian·2024·CVSS 5.9
CVE-2024-41909 [MEDIUM] CVE-2024-41909: libmina-sshd-java - Like many other SSH implementations, Apache MINA SSHD suffered from the issue th...
Like many other SSH implementations, Apache MINA SSHD suffered from the issue that is more widely known as CVE-2023-48795. An attacker that can intercept traffic between client and server could drop certain packets from the stream, potentially causing client and server to consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack The mitigations to prevent this type of attack were implemented in Apache MINA SSHD 2.12.0, both client and server side. Users are recommended to upgrade to at least this version. Note that both the client and the server implementation must have mitigations applied against this issue, otherwise the connection may still be affected.
Scope: local
forky: resolved
sid: resolved
trixie: resolved
BSD
FreeBSD-SA-23:19.openssh: Prefix Truncation Attack in the SSH protocol
bsd_advisories·2023-12-19·CVSS 5.9
CVE-2023-48795 [MEDIUM] FreeBSD-SA-23:19.openssh: Prefix Truncation Attack in the SSH protocol
FreeBSD-SA-23:19.openssh Security Advisory
The FreeBSD Project
Topic: Prefix Truncation Attack in the SSH protocol
Category: contrib
Module: openssh
Announced: 2023-12-19
Credits: Fabian Bäumer, Marcus Brinkmann, Jörg Schwenk
Affects: All supported versions of FreeBSD.
Corrected: 2023-12-18 16:54:31 UTC (stable/14, 14.0-STABLE)
2023-12-19 20:19:48 UTC (releng/14.0, 14.0-RELEASE-p4)
2023-12-18 17:10:15 UTC (stable/13, 13.2-STABLE)
2023-12-19 20:19:57 UTC (releng/13.2, 13.2-RELEASE-p9)
CVE Name: CVE-2023-48795
Note: While this issue does affect 12.4-STABLE and 12.4-RELEASE, the version
of OpenSSH in 12.4 is old enough the vendor provided patch does not cleanly
apply. As 12.4 goes out of support at the end of December and in order to
quickly get fixes out for 14.0 and 13.2, the FreeBSD Sec
Ubuntu
libssh vulnerability
vendor_ubuntu·2023-12-19
CVE-2023-48795 libssh vulnerability
Title: libssh vulnerability
Summary: A security issue was fixed in libssh.
Fabian Bäumer, Marcus Brinkmann, Jörg Schwenk discovered that the SSH
protocol was vulnerable to a prefix truncation attack. If a remote attacker
was able to intercept SSH communications, extension negotiation messages
could be truncated, possibly leading to certain algorithms and features
being downgraded. This issue is known as the Terrapin attack. This update
adds protocol extensions to mitigate this issue.
Instructions: In general, a standard system update will make all the necessary changes.
Ubuntu
OpenSSH vulnerabilities
vendor_ubuntu·2023-12-19·CVSS 9.8
CVE-2023-48795 [CRITICAL] OpenSSH vulnerabilities
Title: OpenSSH vulnerabilities
Summary: Several security issues were fixed in OpenSSH.
Fabian Bäumer, Marcus Brinkmann, Jörg Schwenk discovered that the SSH
protocol was vulnerable to a prefix truncation attack. If a remote attacker
was able to intercept SSH communications, extension negotiation messages
could be truncated, possibly leading to certain algorithms and features
being downgraded. This issue is known as the Terrapin attack. This update
adds protocol extensions to mitigate this issue. (CVE-2023-48795)
Luci Stanescu discovered that OpenSSH incorrectly added destination
constraints when smartcard keys were added to ssh-agent, contrary to
expectations. This issue only affected Ubuntu 22.04 LTS, and Ubuntu 23.04.
(CVE-2023-28531)
Instructions: In general, a standard system updat
Red Hat
ssh: Prefix truncation attack on Binary Packet Protocol (BPP)
vendor_redhat·2023-12-18·CVSS 5.9
CVE-2023-48795 [MEDIUM] CWE-222 ssh: Prefix truncation attack on Binary Packet Protocol (BPP)
ssh: Prefix truncation attack on Binary Packet Protocol (BPP)
The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against SSH's use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in [email protected] and (if CBC is use
Microsoft
The SSH transport protocol with certain OpenSSH extensions found in OpenSSH before 9.6 and other products allows remote attackers to bypass integrity checks such that some packets are omitted (from th
vendor_msrc·2023-12-12·CVSS 5.9
CVE-2023-48795 [MEDIUM] CWE-354 The SSH transport protocol with certain OpenSSH extensions found in OpenSSH before 9.6 and other products allows remote attackers to bypass integrity checks such that some packets are omitted (from th
The SSH transport protocol with certain OpenSSH extensions found in OpenSSH before 9.6 and other products allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message) and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP) implemented by these extensions mishandles the handshake phase and mishandles use of sequence numbers. For example there is an effective attack against SSH's use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in [email protected] and (if CBC is used) the [email protected] MAC algorithms. This also affects Maverick Syn
Debian
CVE-2023-48795: dropbear - The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH bef...
vendor_debian·2023·CVSS 5.9
CVE-2023-48795 [MEDIUM] CVE-2023-48795: dropbear - The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH bef...
The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against SSH's use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in [email protected] and (if CBC is used) the [email protected] MAC algorithms. This also affects Maver
OSV
ProFTPD vulnerabilities
osv·2025-02-25·CVSS 5.9
CVE-2023-48795 [MEDIUM] ProFTPD vulnerabilities
ProFTPD vulnerabilities
Fabian Bäumer, Marcus Brinkmann, and Jörg Schwenk discovered that the
transport protocol implementation in ProFTPD had weak integrity checks.
An attacker could use this vulnerability to bypass security features
like encryption and integrity checks. (CVE-2023-48795)
Martin Mirchev discovered that ProFTPD did not properly validate user
input over the network. An attacker could use this vulnerability to
crash ProFTPD or execute arbitrary code. (CVE-2023-51713)
Brian Ristuccia discovered that ProFTPD incorrectly inherited groups
from the parent process. An attacker could use this vulnerability to
elevate privileges. (CVE-2024-48651)
OSV
Several security issues were fixed in Dropbear
osv·2025-02-25·CVSS 7.5
CVE-2021-36369 [HIGH] Several security issues were fixed in Dropbear
Several security issues were fixed in Dropbear
Manfred Kaiser discovered that Dropbear through 2020.81 does not properly
check the available authentication methods in the client-side SSH code.
An attacker could use this vulnerability to gain unauthorized access to
remote systems. (CVE-2021-36369)
Fabian Bäumer, Marcus Brinkmann, and Jörg Schwenk discovered that the SSH
transport protocol implementation in Dropbear had weak integrity checks.
An attacker could use this vulnerability to bypass security features
like encryption and integrity checks. (CVE-2023-48795)
OSV
Apache MINA SSHD: integrity check bypass
osv·2024-08-12·CVSS 5.9
CVE-2024-41909 [MEDIUM] Apache MINA SSHD: integrity check bypass
Apache MINA SSHD: integrity check bypass
Like many other SSH implementations, Apache MINA SSHD suffered from the issue that is more widely known as CVE-2023-48795. An attacker that can intercept traffic between client and server could drop certain packets from the stream, potentially causing client and server to consequently end up with a connection for which
some security features have been downgraded or disabled, aka a Terrapin
attack
The mitigations to prevent this type of attack were implemented in Apache MINA SSHD 2.12.0, both client and server side. Users are recommended to upgrade to at least this version. Note that both the client and the server implementation must have mitigations applied against this issue, otherwise the connection may still be affected.
GHSA
Apache MINA SSHD: integrity check bypass
ghsa·2024-08-12·CVSS 5.9
CVE-2024-41909 [MEDIUM] CWE-354 Apache MINA SSHD: integrity check bypass
Apache MINA SSHD: integrity check bypass
Like many other SSH implementations, Apache MINA SSHD suffered from the issue that is more widely known as CVE-2023-48795. An attacker that can intercept traffic between client and server could drop certain packets from the stream, potentially causing client and server to consequently end up with a connection for which
some security features have been downgraded or disabled, aka a Terrapin
attack
The mitigations to prevent this type of attack were implemented in Apache MINA SSHD 2.12.0, both client and server side. Users are recommended to upgrade to at least this version. Note that both the client and the server implementation must have mitigations applied against this issue, otherwise the connection may still be affected.
OSV
openssh vulnerabilities
osv·2024-01-11·CVSS 5.9
[MEDIUM] openssh vulnerabilities
openssh vulnerabilities
USN-6560-1 fixed several vulnerabilities in OpenSSH. This update provides
the corresponding update for Ubuntu 16.04 LTS and Ubuntu 18.04 LTS.
Original advisory details:
Fabian Bäumer, Marcus Brinkmann, Jörg Schwenk discovered that the SSH
protocol was vulnerable to a prefix truncation attack. If a remote attacker
was able to intercept SSH communications, extension negotiation messages
could be truncated, possibly leading to certain algorithms and features
being downgraded. This issue is known as the Terrapin attack. This update
adds protocol extensions to mitigate this issue. (CVE-2023-48795)
It was discovered that OpenSSH incorrectly handled user names or host names
with shell metacharacters. An attacker could possibly use this issue to
perform OS command injec
OSV
openssh vulnerabilities
osv·2023-12-19·CVSS 9.8
CVE-2023-48795 [CRITICAL] openssh vulnerabilities
openssh vulnerabilities
Fabian Bäumer, Marcus Brinkmann, Jörg Schwenk discovered that the SSH
protocol was vulnerable to a prefix truncation attack. If a remote attacker
was able to intercept SSH communications, extension negotiation messages
could be truncated, possibly leading to certain algorithms and features
being downgraded. This issue is known as the Terrapin attack. This update
adds protocol extensions to mitigate this issue. (CVE-2023-48795)
Luci Stanescu discovered that OpenSSH incorrectly added destination
constraints when smartcard keys were added to ssh-agent, contrary to
expectations. This issue only affected Ubuntu 22.04 LTS, and Ubuntu 23.04.
(CVE-2023-28531)
GHSA
Prefix Truncation Attack against ChaCha20-Poly1305 and Encrypt-then-MAC aka Terrapin
ghsa·2023-12-18
CVE-2023-48795 [MEDIUM] CWE-345 Prefix Truncation Attack against ChaCha20-Poly1305 and Encrypt-then-MAC aka Terrapin
Prefix Truncation Attack against ChaCha20-Poly1305 and Encrypt-then-MAC aka Terrapin
### Summary
Terrapin is a prefix truncation attack targeting the SSH protocol. More precisely, Terrapin breaks the integrity of SSH's secure channel. By carefully adjusting the sequence numbers during the handshake, an attacker can remove an arbitrary amount of messages sent by the client or server at the beginning of the secure channel without the client or server noticing it.
### Mitigations
To mitigate this protocol vulnerability, OpenSSH suggested a so-called "strict kex" which alters the SSH handshake to ensure a Man-in-the-Middle attacker cannot introduce unauthenticated messages as well as convey sequence number manipulation across handshakes.
**Warning: To take effect, both the client and serv
OSV
Prefix Truncation Attack against ChaCha20-Poly1305 and Encrypt-then-MAC aka Terrapin
osv·2023-12-18
CVE-2023-48795 [MEDIUM] Prefix Truncation Attack against ChaCha20-Poly1305 and Encrypt-then-MAC aka Terrapin
Prefix Truncation Attack against ChaCha20-Poly1305 and Encrypt-then-MAC aka Terrapin
### Summary
Terrapin is a prefix truncation attack targeting the SSH protocol. More precisely, Terrapin breaks the integrity of SSH's secure channel. By carefully adjusting the sequence numbers during the handshake, an attacker can remove an arbitrary amount of messages sent by the client or server at the beginning of the secure channel without the client or server noticing it.
### Mitigations
To mitigate this protocol vulnerability, OpenSSH suggested a so-called "strict kex" which alters the SSH handshake to ensure a Man-in-the-Middle attacker cannot introduce unauthenticated messages as well as convey sequence number manipulation across handshakes.
**Warning: To take effect, both the client and serv
OSV
CVE-2023-48795: The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9
osv·2023-12-18·CVSS 5.9
CVE-2023-48795 [MEDIUM] CVE-2023-48795: The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9
The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against SSH's use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in [email protected] and (if CBC is used) the [email protected] MAC algorithms. This also affects Maver
OSV
Man-in-the-middle attacker can compromise integrity of secure channel in golang.org/x/crypto
osv·2023-12-18
CVE-2023-48795 Man-in-the-middle attacker can compromise integrity of secure channel in golang.org/x/crypto
Man-in-the-middle attacker can compromise integrity of secure channel in golang.org/x/crypto
A protocol weakness allows a MITM attacker to compromise the integrity of the secure channel before it is established, allowing the attacker to prevent transmission of a number of messages immediately after the secure channel is established without either side being aware.
The impact of this attack is relatively limited, as it does not compromise confidentiality of the channel. Notably this attack would allow an attacker to prevent the transmission of the SSH2_MSG_EXT_INFO message, disabling a handful of newer security features.
This protocol weakness was also fixed in OpenSSH 9.6.
VulnCheck
OpenBSD openssh Improper Validation of Integrity Check Value
vulncheck·2023·CVSS 5.9
CVE-2023-48795 [MEDIUM] OpenBSD openssh Improper Validation of Integrity Check Value
OpenBSD openssh Improper Validation of Integrity Check Value
The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against SSH's use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in [email protected] and (if CBC is used
No detection rules found.
Nuclei
OpenSSH Terrapin Attack - Detection
nuclei·CVSS 5.9
CVE-2023-48795 [MEDIUM] OpenSSH Terrapin Attack - Detection
OpenSSH Terrapin Attack - Detection
The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against SSH's use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in [email protected] and (if CBC is used) the [email protected] MA
Wiz
Crying Out Cloud - January Newsletter | Wiz
blogs_wiz·2024-01-01·CVSS 8.8
CVE-2023-26360 [HIGH] Crying Out Cloud - January Newsletter | Wiz
This month we’ve seen several vulnerabilities and security incidents that have left users affected. We know you're busy too, so we've sifted through the noise to bring you the real game-changers.
Here are our top picks!
## 🐞 High Profile Vulnerabilities
Adobe ColdFusion RCE vulnerability exploited in-the-wild
CVE-2023-26360 is a critical vulnerability in Adobe ColdFusion that was published in March 2023. This vulnerability could allow an attacker to execute arbitrary code on the remote server in the context of the current user. On December 5, 2023, CISA announced that threat actors were actively exploiting this vulnerability in order to gain initial access to government-owned servers. Customers should update Adobe ColdFusion to the latest version.
According to Wiz data, less than 1% o
Qualys
Mitigate SSH Vulnerability CVE-2023-48795 with Qualys CSAM | Qualys
blogs_qualys·2023-12-22·CVSS 5.9
CVE-2023-48795 [MEDIUM] Mitigate SSH Vulnerability CVE-2023-48795 with Qualys CSAM | Qualys
#### Table of Contents
- Why Are the Terrapin Attacks So Important?
- What Is SSH Vulnerability CVE-2023-48795?
- Vulnerable Versions
- What Does This Mean for You?
- What Should Organizations Do?
- Take Action With the Enterprise TruRisk Platform
- Additional Resources
- Contributors
Secure Shell Protocol (SSH) has been a cornerstone of cryptography and security since it was developed in early 1995. Organizations rely on SSH for secure communications within several popular software products. The recent Terrapin Attack highlights the importance of maintaining full visibility of your attack surface and the urgency required to identify all external-facing instances of the SSH vulnerability that can be exploited by attackers.
In this blog post, we’ll provide context into the SSH vulnerabil
Qualys
SSH Attack Surface (CVE-2023-48795): Find and Patch With CyberSecurity Asset Management Before the Grinch Arrives
blogs_qualys·2023-12-22·CVSS 5.9
CVE-2023-48795 [MEDIUM] SSH Attack Surface (CVE-2023-48795): Find and Patch With CyberSecurity Asset Management Before the Grinch Arrives
## Table of Contents
Why Are the Terrapin Attacks So Important?
What Is SSH Vulnerability CVE-2023-48795?
Vulnerable Versions
What Does This Mean for You?
What Should Organizations Do?
Take Action With the Enterprise TruRisk Platform
Additional Resources
Contributors
Secure Shell Protocol (SSH) has been a cornerstone of cryptography and security since it was developed in early 1995. Organizations rely on SSH for secure communications within several popular software products. The recent Terrapin Attack highlights the importance of maintaining full visibility of your attack surface and the urgency required to identify all external-facing instances of the SSH vulnerability that can be exploited by attackers.
In this blog post, we’ll provide context into the SSH vulnerability and sho
Bleepingcomputer
Terrapin attacks can downgrade security of OpenSSH connections
blogs_bleepingcomputer·2023-12-19·CVSS 5.9
[MEDIUM] Terrapin attacks can downgrade security of OpenSSH connections
## Terrapin attacks can downgrade security of OpenSSH connections
## Bill Toulas
Academic researchers developed a new attack called Terrapin that manipulates sequence numbers during the handshake process to break the SSH channel integrity when certain widely-used encryption modes are used.
This manipulation lets attackers remove or modify messages exchanged through the communication channel, which leads to downgrading the public key algorithms used for user authentication or disabling defenses against keystroke timing attacks in OpenSSH 9.5.
A Terrapin attack lowers the security of the established connection by truncating important negotiation messages without the client or server noticing it.
Researchers from the Ruhr University Bochum developed the Terrapin attack and also discovere
Wiz
CVE-2026-4115 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 7.5
CVE-2026-4115 [HIGH] CVE-2026-4115 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-4115 :
PuTTY vulnerability analysis and mitigation
A vulnerability was detected in PuTTY 0.83. Affected is the function eddsa_verify of the file crypto/ecc-ssh.c of the component Ed25519 Signature Handler. The manipulation results in improper verification of cryptographic signature. The attack may be performed from remote. The attack requires a high level of complexity. The exploitability is told to be difficult. The exploit is now public and may be used. The real existence of this vulnerability is still doubted at the moment. The patch is identified as af996b5ec27ab79bae3882071b9d6acf16044549. It is advisable to implement a patch to correct this issue. The vendor was contacted early, responded in a very professional manner and quickly released a patch for the affected produc
Wiz
CVE-2023-53959 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 6.3
CVE-2023-53959 [MEDIUM] CVE-2023-53959 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2023-53959 :
FileZilla FTP Client vulnerability analysis and mitigation
FileZilla Client 3.63.1 contains a DLL hijacking vulnerability that allows attackers to execute malicious code by placing a crafted TextShaping.dll in the application directory. Attackers can generate a reverse shell payload using msfvenom and replace the missing DLL to achieve remote code execution when the application launches.
Source : NVD
## 8.5
Score
Published December 19, 2025
Severity HIGH
CNA Score 8.5
Affected Technologies
FileZilla FTP Client
Has Public Exploit Yes
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 52.7
Exploitation Probability (EPSS) 0.3
Affected packages and libraries
cpe:2.3:a:filezilla-project:filez
Huntress
CVE-2023-48795 Vulnerability: Analysis, Impact, Mitigation | Huntress
blogs_huntress·CVSS 5.9
CVE-2023-48795 [MEDIUM] CVE-2023-48795 Vulnerability: Analysis, Impact, Mitigation | Huntress
## CVE-2023-48795 Vulnerability
Written by: Monica Burgess
Published: 12/03/2025
CVE-2023-48795, also known as the Terrapin attack, is a prefix truncation vulnerability in the SSH protocol. This flaw allows a man-in-the-middle (MitM) attacker to downgrade connection security by manipulating sequence numbers during the handshake. The result? Attackers can delete messages at the beginning of the secure channel, compromising the integrity of the connection.
## What is CVE-2023-48795 Vulnerability?
CVE-2023-48795 is a significant vulnerability within the Secure Shell (SSH) transport protocol. It enables a MitM attacker to bypass integrity checks by truncating the initial messages exchanged during a secure handshake. By carefully manipulating sequence numbers, an attacker can delete a spec
Wiz
CVE-2021-47865 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 9.3
CVE-2021-47865 [CRITICAL] CVE-2021-47865 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2021-47865 :
ProFTPd vulnerability analysis and mitigation
ProFTPD 1.3.7a contains a denial of service vulnerability that allows attackers to overwhelm the server by creating multiple simultaneous FTP connections. Attackers can repeatedly establish connections using threading to exhaust server connection limits and block legitimate user access.
Source : NVD
## 8.7
Score
Published January 21, 2026
Severity HIGH
CNA Score 8.7
Affected Technologies
ProFTPd
Has Public Exploit Yes
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 5.3
Exploitation Probability (EPSS) N/A
Affected packages and libraries
cpe:2.3:a:proftpd:proftpd
Sources
NVD
Linux Severity HIGH No Fix Added at: Jan 23, 2026
## Get a CVE
Wiz
CVE-2025-11961 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 7.5
CVE-2025-11961 [HIGH] CVE-2025-11961 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2025-11961 :
Nmap vulnerability analysis and mitigation
pcap_ether_aton() is an auxiliary function in libpcap, it takes a string argument and returns a fixed-size allocated buffer. The string argument must be a well-formed MAC-48 address in one of the supported formats, but this requirement has been poorly documented. If an application calls the function with an argument that deviates from the expected format, the function can read data beyond the end of the provided string and write data beyond the end of the allocated buffer.
Source : NVD
## 1.9
Score
Published December 31, 2025
Severity LOW
CNA Score 1.9
Affected Technologies
Nmap
CBL Mariner
Has Public Exploit No
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Pe
Wiz
CVE-2019-25683 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 6.3
CVE-2019-25683 [MEDIUM] CVE-2019-25683 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2019-25683 :
FileZilla FTP Client vulnerability analysis and mitigation
FileZilla 3.40.0 contains a denial of service vulnerability in the local search functionality that allows local attackers to crash the application by supplying a malformed path string. Attackers can trigger the crash by entering a crafted path containing 384 'A' characters followed by 'BBBB' and 'CCCC' sequences in the search directory field and initiating a local search operation.
Source : NVD
## 6.9
Score
Published April 5, 2026
Severity MEDIUM
CNA Score 6.9
Affected Technologies
FileZilla FTP Client
Has Public Exploit Yes
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 1.6
Exploitation Probability (EPSS) N/A
Affected package
HackerOne
Weak ssh algorithms and CVE-2023-48795 Discovered on various subdomains of nextcloud.com
hackerone·2024-05-22·CVSS 5.9
CVE-2023-48795 [MEDIUM] Weak ssh algorithms and CVE-2023-48795 Discovered on various subdomains of nextcloud.com
Weak ssh algorithms and CVE-2023-48795 Discovered on various subdomains of nextcloud.com
Security researchers from Ruhr University Bochum have discovered a vulnerability in the Secure Shell (**[SSH](https://en.wikipedia.org/wiki/Secure_Shell)**) cryptographic network protocol that could allow an attacker to downgrade the connection's security by breaking the integrity of the secure channel.
Called **Terrapin** (**[CVE-2023-48795](https://nvd.nist.gov/vuln/detail/CVE-2023-48795)**, CVSS score: 5.9), the exploit has been described as the "first-ever practically exploitable prefix truncation attack."
In a real-world scenario, an attacker could exploit this vulnerability to intercept sensitive data or gain control over critical systems using administrator-privileged access.
Weak SSH algori
Bugzilla
CVE-2023-48795 ssh: Prefix truncation attack on Binary Packet Protocol (BPP)
bugzilla·2023-12-12·CVSS 5.9
CVE-2023-48795 [MEDIUM] CVE-2023-48795 ssh: Prefix truncation attack on Binary Packet Protocol (BPP)
CVE-2023-48795 ssh: Prefix truncation attack on Binary Packet Protocol (BPP)
Prefix truncation attack on BPP: By manipulating sequence numbers during the handshake, an attacker can remove the initial messages on the secure
channel without causing a MAC failure. The vulnerable cipher modes are ChaCha20-Poly1305 ([email protected]) and Encrypt-then-MAC ([email protected] MAC algorithms).
Discussion:
Created age tracking bugs for this issue:
Affects: fedora-all [bug 2255071]
Created ansible-collection-ansible-netcommon tracking bugs for this issue:
Affects: fedora-all [bug 2255055]
Affects: openstack-rdo [bug 2255059]
Created apptainer tracking bugs for this issue:
Affects: epel-all [bug 2255062]
Affects: fedora-all [bug 2255072]
Created buildah tracking bugs for this i
arXiv
Terrapin Attack: Breaking SSH Channel Integrity By Sequence Number Manipulation
arxiv_fulltext·2024-05-07
Terrapin Attack: Breaking SSH Channel Integrity By Sequence Number Manipulation
## Abstract
The SSH protocol provides secure access to network services, particularly
remote terminal login and file transfer within organizational networks and to
over 15 million servers on the open internet. SSH uses an authenticated key
exchange to establish a secure channel between a client and a server,
which protects the confidentiality and integrity of messages sent in either
direction. The secure channel prevents message manipulation, replay, insertion,
deletion, and reordering. At the network level, SSH uses the Binary
Packet Protocol over TCP.
In this paper, we show that as new encryption algorithms and mitigations were
added to SSH, the SSH Binary Packet Protocol is no longer a secure channel: SSH
channel integrity (INT-PST, aINT-PTXT, and INT-sfCTF) is broken for three
widely
http://packetstormsecurity.com/files/176280/Terrapin-SSH-Connection-Weakening.htmlhttp://seclists.org/fulldisclosure/2024/Mar/21http://www.openwall.com/lists/oss-security/2023/12/18/3http://www.openwall.com/lists/oss-security/2023/12/19/5http://www.openwall.com/lists/oss-security/2023/12/20/3http://www.openwall.com/lists/oss-security/2024/03/06/3http://www.openwall.com/lists/oss-security/2024/04/17/8https://access.redhat.com/security/cve/cve-2023-48795https://arstechnica.com/security/2023/12/hackers-can-break-ssh-channel-integrity-using-novel-data-corruption-attack/https://bugs.gentoo.org/920280https://bugzilla.redhat.com/show_bug.cgi?id=2254210https://bugzilla.suse.com/show_bug.cgi?id=1217950https://crates.io/crates/thrussh/versionshttps://filezilla-project.org/versions.phphttps://forum.netgate.com/topic/184941/terrapin-ssh-attackhttps://git.libssh.org/projects/libssh.git/commit/?h=stable-0.10&id=10e09e273f69e149389b3e0e5d44b8c221c2e7f6https://github.com/NixOS/nixpkgs/pull/275249https://github.com/PowerShell/Win32-OpenSSH/issues/2189https://github.com/PowerShell/Win32-OpenSSH/releases/tag/v9.5.0.0p1-Betahttps://github.com/TeraTermProject/teraterm/commit/7279fbd6ef4d0c8bdd6a90af4ada2899d786eec0https://github.com/TeraTermProject/teraterm/releases/tag/v5.1https://github.com/advisories/GHSA-45x7-px36-x8w8https://github.com/apache/mina-sshd/issues/445https://github.com/connectbot/sshlib/commit/5c8b534f6e97db7ac0e0e579331213aa25c173abhttps://github.com/connectbot/sshlib/compare/2.2.21...2.2.22https://github.com/cyd01/KiTTY/issues/520https://github.com/drakkan/sftpgo/releases/tag/v2.5.6https://github.com/erlang/otp/blob/d1b43dc0f1361d2ad67601169e90a7fc50bb0369/lib/ssh/doc/src/notes.xml#L39-L42https://github.com/erlang/otp/releases/tag/OTP-26.2.1https://github.com/golang/crypto/commit/9d2ee975ef9fe627bf0a6f01c1f69e8ef1d4f05dhttps://github.com/hierynomus/sshj/issues/916https://github.com/janmojzis/tinyssh/issues/81https://github.com/jtesta/ssh-audit/commit/8e972c5e94b460379fe0c7d20209c16df81538a5https://github.com/libssh2/libssh2/pull/1291https://github.com/mkj/dropbear/blob/17657c36cce6df7716d5ff151ec09a665382d5dd/CHANGES#L25https://github.com/mscdex/ssh2/commit/97b223f8891b96d6fc054df5ab1d5a1a545da2a3https://github.com/mwiede/jsch/compare/jsch-0.2.14...jsch-0.2.15https://github.com/mwiede/jsch/issues/457https://github.com/mwiede/jsch/pull/461https://github.com/net-ssh/net-ssh/blob/2e65064a52d73396bfc3806c9196fc8108f33cd8/CHANGES.txt#L14-L16https://github.com/openssh/openssh-portable/commits/masterhttps://github.com/paramiko/paramiko/issues/2337https://github.com/proftpd/proftpd/blob/0a7ea9b0ba9fcdf368374a226370d08f10397d99/RELEASE_NOTEShttps://github.com/proftpd/proftpd/blob/d21e7a2e47e9b38f709bec58e3fa711f759ad0e1/RELEASE_NOTEShttps://github.com/proftpd/proftpd/blob/master/RELEASE_NOTEShttps://github.com/proftpd/proftpd/issues/456https://github.com/rapier1/hpn-ssh/releaseshttps://github.com/ronf/asyncssh/blob/develop/docs/changes.rsthttps://github.com/ronf/asyncssh/tagshttps://github.com/ssh-mitm/ssh-mitm/issues/165https://github.com/warp-tech/russh/releases/tag/v0.40.2https://gitlab.com/libssh/libssh-mirror/-/tagshttps://groups.google.com/g/golang-announce/c/-n5WqVC18LQhttps://groups.google.com/g/golang-announce/c/qA3XtxvMUyghttps://help.panic.com/releasenotes/transmit5/https://jadaptive.com/important-java-ssh-security-update-new-ssh-vulnerability-discovered-cve-2023-48795/https://lists.debian.org/debian-lts-announce/2023/12/msg00017.htmlhttps://lists.debian.org/debian-lts-announce/2024/01/msg00013.htmlhttps://lists.debian.org/debian-lts-announce/2024/01/msg00014.htmlhttps://lists.debian.org/debian-lts-announce/2024/04/msg00016.htmlhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/33XHJUB6ROFUOH2OQNENFROTVH6MHSHA/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3CAYYW35MUTNO65RVAELICTNZZFMT2XS/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3JIMLVBDWOP4FUPXPTB4PGHHIOMGFLQE/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3YQLUQWLIHDB5QCXQEX7HXHAWMOKPP5O/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6Y74KVCPEPT4MVU3LHDWCNNOXOE5ZLUR/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APYIXIQOVDCRWLHTGB4VYMAUIAQLKYJ3/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BL5KTLOSLH2KHRN4HCXJPK3JUVLDGEL6/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/C3AFMZ6MH2UHHOPIWT5YLSFV3D2VB3AC/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CHHITS4PUOZAKFIUBQAQZC7JWXMOYE4B/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/F7EYCFQCTSGJXWO3ZZ44MGKFC5HA7G3Y/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HYEDEXIKFKTUJIN43RG4B7T5ZS6MHUSP/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I724O3LSRCPO4WNVIXTZCT4VVRMXMMSG/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KEOTKBUPZXHE3F352JBYNTSNRXYLWD6P/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KMZCVGUGJZZVDPCVDA7TEB22VUCNEXDD/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L5Y6MNNVAPIJSXJERQ6PKZVCIUXSNJK7/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LZQVUHWVWRH73YBXUQJOD6CKHDQBU3DM/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MKQRBF3DWMWPH36LBCOBUTSIZRTPEZXB/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QI3EHAHABFQK7OABNCSF5GMYP6TONTI7/https://matt.ucc.asn.au/dropbear/CHANGEShttps://nest.pijul.com/pijul/thrussh/changes/D6H7OWTTMHHX6BTB3B6MNBOBX2L66CBL4LGSEUSAI2MCRCJDQFRQChttps://news.ycombinator.com/item?id=38684904https://news.ycombinator.com/item?id=38685286https://news.ycombinator.com/item?id=38732005https://nova.app/releases/#v11.8https://oryx-embedded.com/download/#changeloghttps://psirt.global.sonicwall.com/vuln-detail/SNWLID-2024-0002https://roumenpetrov.info/secsh/#news20231220https://security-tracker.debian.org/tracker/CVE-2023-48795https://security-tracker.debian.org/tracker/source-package/libssh2https://security-tracker.debian.org/tracker/source-package/proftpd-dfsghttps://security-tracker.debian.org/tracker/source-package/trilead-ssh2https://security.gentoo.org/glsa/202312-16https://security.gentoo.org/glsa/202312-17https://security.netapp.com/advisory/ntap-20240105-0004/https://support.apple.com/kb/HT214084https://thorntech.com/cve-2023-48795-and-sftp-gateway/https://twitter.com/TrueSkrillor/status/1736774389725565005https://ubuntu.com/security/CVE-2023-48795https://winscp.net/eng/docs/history#6.2.2https://www.bitvise.com/ssh-client-version-history#933
+ 157 more references
2023-12-18
Published
Exploited in the wild