CVE-2023-51767 — OpenSSH through 10

OpenSSH through 10.0, when common types of DRAM are used, might allow row hammer attacks (for authentication bypass) because the integer value of authenticated in mm_answer_authpassword does not resist flips of a single bit. NOTE: this is applicable to a certain threat model of a

01What is this vulnerability?

OpenSSH through 10.0, when common types of DRAM are used, might allow row hammer attacks (for authentication bypass) because the integer value of authenticated in mm_answer_authpassword does not resist flips of a single bit. NOTE: this is applicable to a certain threat model of attacker-victim co-location in which the attacker has user privileges. NOTE: this is disputed by the Supplier, who…

02Affected products

No structured affected-product list available — see references below for vendor advisories.

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-12-24T07:15:07.410
• Last modified: 2026-10-15T01:17:12.797

09References

• access.redhat.com — https://access.redhat.com/security/cve/CVE-2023-51767
• arxiv.org — https://arxiv.org/abs/2309.02545
• bugzilla.redhat.com — https://bugzilla.redhat.com/show_bug.cgi?id=2255850
• github.com — https://github.com/openssh/openssh-portable/blob/8241b9c0529228b4b86d88b1a6076fb…
• github.com — https://github.com/openssh/openssh-portable/blob/8241b9c0529228b4b86d88b1a6076fb…
• security.netapp.com — https://security.netapp.com/advisory/ntap-20240125-0006/
• ubuntu.com — https://ubuntu.com/security/CVE-2023-51767
• www.openwall.com — https://www.openwall.com/lists/oss-security/2025/09/22/1
• www.openwall.com — http://www.openwall.com/lists/oss-security/2025/09/22/1
• www.openwall.com — http://www.openwall.com/lists/oss-security/2025/09/22/2