Vulnerability in OpenBSD OpenSSH
CVE-2023-51767
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 states "we do not consider it to be the application's responsibility to defend against platform architectural weaknesses."
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.007 (49.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000
Affected products
- OpenBSD OpenSSH
- Fedoraproject Fedora — versions 39
- Red Hat Enterprise Linux — versions 8.0, 9.0
Public proof-of-concept exploits
References
- arxiv.org/abs/2309.02545 (Technical Description)
- github.com/openssh/openssh-portable/blob/8241b9c0529228b4b86d88b1a6076fb9f97e4a… (Product)
- github.com/openssh/openssh-portable/blob/8241b9c0529228b4b86d88b1a6076fb9f97e4a… (Product)
- bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
- access.redhat.com/security/cve/CVE-2023-51767 (Third Party Advisory)
- ubuntu.com/security/CVE-2023-51767 (Third Party Advisory)
- security.netapp.com/advisory/ntap-20240125-0006/ (Third Party Advisory)
- www.openwall.com/lists/oss-security/2025/09/22/1
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2023-51767?
- CVE-2023-51767 is a high-severity vulnerability in OpenBSD OpenSSH. CVSS score: 7.0/10. Published 2023-12-24.
- How severe is CVE-2023-51767?
- High severity. CVSS v3 base score is 7.0 out of 10.
- Is CVE-2023-51767 known to be exploited?
- 5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.