CVE-2023-51384

Publication date 20 December 2023

Last updated 26 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

In ssh-agent in OpenSSH before 9.6, certain destination constraints can be incompletely applied. When destination constraints are specified during addition of PKCS#11-hosted private keys, these constraints are only applied to the first key, even if a PKCS#11 token returns multiple keys.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
openssh	24.10 oracular	Fixed 1:9.6p1-3ubuntu1
	24.04 LTS noble	Fixed 1:9.6p1-3ubuntu1
	23.10 mantic	Fixed 1:9.3p1-1ubuntu3.2
	23.04 lunar	Fixed 1:9.0p1-1ubuntu8.7
	22.04 LTS jammy	Fixed 1:8.9p1-3ubuntu0.6
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected
openssh-ssh1	24.10 oracular	Ignored
	24.04 LTS noble	Ignored
	23.10 mantic	Ignored end of life, was needs-triage
	23.04 lunar	Ignored end of life, was needs-triage
	22.04 LTS jammy	Ignored
	20.04 LTS focal	Ignored
	18.04 LTS bionic	Ignored
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release

Notes

mdeslaur

openssh-ssh1 is only provided for compatibility with old devices that cannot be upgraded to modern protocols. We will not be providing any security support for the openssh-ssh1 package as it is insecure and should be used in trusted environments only. destination constraints were added in 8.9

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
openssh	Upstream: 881d9c6

Severity score breakdown

Parameter	Value
Base score	5.5 · Medium
Attack vector	Local
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	None
Availability impact	None
Vector	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

References

Related Ubuntu Security Notices (USN)

USN-6565-1
OpenSSH vulnerabilities
3 January 2024