CVE-2021-20093
published 2021-06-16CVE-2021-20093: A buffer over-read vulnerability exists in Wibu-Systems CodeMeter versions < 7.21a. An unauthenticated remote attacker can exploit this issue to disclose heap…
PriorityP266critical9.1CVSS 3.1
AVNACLPRNUINSUCHINAH
EPSS
33.30%
98.2th percentile
A buffer over-read vulnerability exists in Wibu-Systems CodeMeter versions < 7.21a. An unauthenticated remote attacker can exploit this issue to disclose heap memory contents or crash the CodeMeter Runtime Server.
Affected
14 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| siemens | simatic_information_server | — | — |
| siemens | simatic_information_server | — | — |
| siemens | simatic_pcs_neo | < 3.1 | 3.1 |
| siemens | simatic_process_historian | — | — |
| siemens | simatic_process_historian | >= 2019 < 2020 | 2020 |
| siemens | simatic_wincc_oa | — | — |
| siemens | simatic_wincc_oa | — | — |
| siemens | simit_simulation_platform | — | — |
| siemens | simit_simulation_platform | >= 10.0 < 10.3 | 10.3 |
| siemens | sinec_infrastructure_network_services | < 1.0.1.1 | 1.0.1.1 |
| siemens | sinec_infrastructure_network_services | — | — |
| siemens | sinema_remote_connect_server | < 3.0 | 3.0 |
| siemens | sinema_remote_connect_server | — | — |
| wibu | codemeter | <= 7.21a | — |
Detection & IOCsextracted from sources · hover to see the quote
commandpython3 -c "import os,struct; size=0x200; os.write(1,b'samc'+struct.pack('<I',size)+b'\x00'*(size-8))" | nc <target> <CmLAN_port>↗
commandpython3 -c "import os,struct; size=0x1000000; os.write(1,b'samc'+struct.pack('<I',size)+b'\x00'*(size-8))" | nc <target> <CmLAN_port> > /dev/null↗
bytes↗
\xA2\x05 (unencrypted message trigger prefix)
- →Detect exploit attempts by monitoring for network packets sent to the CmLAN port whose payload begins with the magic bytes 'samc' followed by an attacker-controlled 4-byte little-endian size field larger than 0x100 (256), indicating an attempted buffer over-read. ↗
- →Alert on unencrypted CmLAN messages whose body starts with '\xA2\x05' arriving from non-localhost sources, as the server should only accept such messages from localhost when properly hardened. ↗
- →Monitor for unexpected crashes or access violation exceptions (code c0000005) in CodeMeter.exe, particularly involving a faulting instruction of 'rep movs' (f3 a4), which is the exact instruction triggered by the buffer over-read PoC. ↗
- →Use a host-based firewall to restrict access to the CmLAN port from remote hosts; any remote connection attempt to this port from non-localhost addresses should be treated as suspicious. ↗
- ·The CmLAN network server is disabled by default; the vulnerability is only exploitable remotely if the CodeMeter network server has been explicitly enabled. Binding to localhost also prevents remote exploitation. ↗
- ·The heap buffer targeted is fixed at 0x100 (256) bytes; copy sizes larger than this value (attacker-controlled) trigger the over-read. Detection logic should flag size fields exceeding 0x100 in CmLAN messages. ↗
CVSS provenance
nvdv3.19.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
nvdv2.06.4MEDIUMAV:N/AC:L/Au:N/C:P/I:N/A:P
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GHSA
GHSA-m5xx-rgqg-j2m6: A buffer over-read vulnerability exists in Wibu-Systems CodeMeter versions < 7
ghsa_unreviewed·2022-05-24
CVE-2021-20093 [CRITICAL] CWE-125 GHSA-m5xx-rgqg-j2m6: A buffer over-read vulnerability exists in Wibu-Systems CodeMeter versions < 7
A buffer over-read vulnerability exists in Wibu-Systems CodeMeter versions < 7.21a. An unauthenticated remote attacker can exploit this issue to disclose heap memory contents or crash the CodeMeter Runtime Server.
CISA ICS
Siemens Desigo CC product family
cisa_ics·2023-11-16·CVSS 9.1
[CRITICAL] Siemens Desigo CC product family
ICS Advisory
##
Siemens Desigo CC product family
Release DateNovember 16, 2023
Alert CodeICSA-23-320-03
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 9.1
- ATTENTION: Exploitable remotely/Low attack complexity
- Vendor: Siemens
- Equipment: Desigo CC product family
- Vulnerabilities: Buffer Over-Read, Heap-Based Buffer Overflow
## 2. RISK EVALUATION
Successful exploitation of these vulnerabilities could allow remote attackers to execute arbitrary c
CISA ICS
Wibu-Systems CodeMeter Runtime
cisa_ics·2021-07-29·CVSS 9.1
[CRITICAL] Wibu-Systems CodeMeter Runtime
## Archived Content In an effort to keep CISA.gov current, the archive contains outdated information that may not reflect current policy or programs.
ICS Advisory
##
Wibu-Systems CodeMeter Runtime
Last RevisedJuly 29, 2021
Alert CodeICSA-21-210-02
## 1. EXECUTIVE SUMMARY
- CVSS v3 9.1
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Wibu-Systems AG
- Equipment: CodeMeter Runtime
- Vulnerabilities: Buffer Over-read
## 2. RISK EVALUATION
Successful exploitation of these vulnerabilities could allow an attacker to read data from the heap of the CodeMeter Runtime network server, or crash the CodeMeter Runtime Server (i.e., CodeMeter.exe).
## 3. TECHNICAL DETAILS
## 3.1 AFFECTED PRODUCTS
The following versions of CodeMete
No detection rules found.
No public exploits indexed.
Checkpoint
6th April – Threat Intelligence Report
blogs_checkpoint·2026-04-06
CVE-2026-20093 6th April – Threat Intelligence Report
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Tenable
Multiple Vulnerabilities in Wibu-Systems CodeMeter
blogs_tenable·2021-06-15
Multiple Vulnerabilities in Wibu-Systems CodeMeter
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Wiz
CVE-2020-37017 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 7.5
CVE-2020-37017 [HIGH] CVE-2020-37017 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2020-37017 :
Wibu-Systems CodeMeter vulnerability analysis and mitigation
CodeMeter 6.60 contains an unquoted service path vulnerability that allows local users to potentially execute arbitrary code with elevated system privileges. Attackers can exploit the unquoted binary path in the CodeMeter Runtime Server service to inject malicious code that would execute with LocalSystem permissions.
Source : NVD
## 8.5
Score
Published January 29, 2026
Severity HIGH
CNA Score 8.5
Affected Technologies
Wibu-Systems CodeMeter
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) 3.8
Exploitation Probability (EPSS) N/A
Affected packages and libraries
cpe:2.3:a:wibu:codemeter
Sources
NVD
Wind
https://cdn.wibu.com/fileadmin/wibu_downloads/security_advisories/Advisory_WIBU-210423-01.pdfhttps://cert-portal.siemens.com/productcert/pdf/ssa-675303.pdfhttps://us-cert.cisa.gov/ics/advisories/icsa-21-210-02https://www.tenable.com/security/research/tra-2021-24https://cdn.wibu.com/fileadmin/wibu_downloads/security_advisories/Advisory_WIBU-210423-01.pdfhttps://cert-portal.siemens.com/productcert/pdf/ssa-675303.pdfhttps://us-cert.cisa.gov/ics/advisories/icsa-21-210-02https://www.tenable.com/security/research/tra-2021-24
2021-06-16
Published