⚠ Exploited in the wild
Exploitation observed in the wild. Not yet on CISA KEV.

CVE-2023-25136Double Free in Openssh

Severity
6.5MEDIUMNVD
EPSS
88.3%
top 0.50%
CISA KEV
Not in KEV
Exploit
Exploited in wild
Active exploitation observed
Timeline
PublishedFeb 3
Latest updateApr 15

Description

OpenSSH server (sshd) 9.1 introduced a double-free vulnerability during options.kex_algorithms handling. This is fixed in OpenSSH 9.2. The double free can be leveraged, by an unauthenticated remote attacker in the default configuration, to jump to any location in the sshd address space. One third-party report states "remote code execution is theoretically possible."

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:HExploitability: 2.2 | Impact: 4.2

Affected Packages2 packages

Debianopenbsd/openssh< 1:9.2p1-1+2

Also affects: Fedora 37, 38

Patches

🔴Vulnerability Details

3
GHSA
GHSA-w62j-g234-3f6f: OpenSSH server (sshd) 92023-02-03
CVEList
CVE-2023-25136: OpenSSH server (sshd) 92023-02-03
OSV
CVE-2023-25136: OpenSSH server (sshd) 92023-02-03

📋Vendor Advisories

5
Oracle
Oracle Oracle HealthCare Applications Risk Matrix: DataStudio (OpenSSH) — CVE-2023-251362023-04-15
BSD
FreeBSD-SA-23:02.openssh: OpenSSH pre-authentication double free2023-02-16
Microsoft
OpenSSH server (sshd) 9.1 introduced a double-free vulnerability during options.kex_algorithms handling. This is fixed in OpenSSH 9.2. The double free can be leveraged, by an unauthenticated remote at2023-02-14
Red Hat
openssh: the functions order_hostkeyalgs() and list_hostkey_types() leads to double-free vulnerability2023-02-03
Debian
CVE-2023-25136: openssh - OpenSSH server (sshd) 9.1 introduced a double-free vulnerability during options....2023

🕵️Threat Intelligence

1
Qualys
CVE-2023-25136: Pre-Auth Double Free Vulnerability in OpenSSH Server 9.1 | Qualys2023-02-03
CVE-2023-25136 — Double Free in Openbsd Openssh | cvebase