CVE-2023-38408

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 79.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2023-07-20 · updated 2026-10-15
Weakness: CWE-428

Description

The PKCS#11 feature in ssh-agent in OpenSSH before 9.3p2 has an insufficiently trustworthy search path, leading to remote code execution if an agent is forwarded to an attacker-controlled system. (Code in /usr/lib is not necessarily safe for loading into ssh-agent.) NOTE: this issue exists because of an incomplete fix for CVE-2016-10009.

Affected products

Fedoraproject Fedora: 37, 38
OpenSSH: before 9.3; 9.3, 9.3-p1 — fixed in 9.3

How to fix

Upgrade to a fixed version: OpenSSH 9.3. Check the vendor advisory for mitigations.

References

http://packetstormsecurity.com/files/173661/OpenSSH-Forwarded-SSH-Agent-Remote-Code-Execution.html
http://www.openwall.com/lists/oss-security/2023/07/20/1
http://www.openwall.com/lists/oss-security/2023/07/20/2
http://www.openwall.com/lists/oss-security/2023/09/22/11
http://www.openwall.com/lists/oss-security/2023/09/22/9
https://blog.qualys.com/vulnerabilities-threat-research/2023/07/19/cve-2023-38408-remote-code-execution-in-opensshs-forwarded-ssh-agent
https://github.com/openbsd/src/commit/7bc29a9d5cd697290aa056e94ecee6253d3425f8
https://github.com/openbsd/src/commit/f03a4faa55c4ce0818324701dadbf91988d7351d
https://github.com/openbsd/src/commit/f8f5a6b003981bb824329dc987d101977beda7ca
https://lists.debian.org/debian-lts-announce/2023/08/msg00021.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CEBTJJINE2I3FHAUKKNQWMFGYMLSMWKQ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RAXVQS6ZYTULFAK3TEJHRLKZALJS3AOU/

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