USN-6560-1: openssh Ubuntu

Published

Published 19-12-2023Last modified 27-04-2026

Vulnerability summary

USN-6560-1 is a vulnerability in openssh Ubuntu with no CVSS score yet.

Priority

Insufficient evidence

No CVSS vector published; no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?

CVSS score

Not scored

010

No CVSS score recorded

EPSS scoreNot scoredRisk metrics not yet published.

KEVNot listedNot listed by any tracked catalog.

RansomwareNot flaggedNo ransomware use recorded.

Public exploits0No public exploits recorded

Advisory lineage

Upstream 2 · Downstream 0 · Related 2

CVE-2023-28531 CVE-2023-48795

Timeline

19-12-2023
PublishedVulnerability first disclosed.
27-04-2026
Last modifiedVulnerability information updated.

Description

openssh vulnerabilities Fabian Bäumer, Marcus Brinkmann, Jörg Schwenk discovered that the SSH protocol was vulnerable to a prefix truncation attack. If a remote attacker was able to intercept SSH communications, extension negotiation messages could be truncated, possibly leading to certain algorithms and features being downgraded. This issue is known as the Terrapin attack. This update adds protocol extensions to mitigate this issue. (CVE-2023-48795) Luci Stanescu discovered that OpenSSH incorrectly added destination constraints when smartcard keys were added to ssh-agent, contrary to expectations. This issue only affected Ubuntu 22.04 LTS, and Ubuntu 23.04. (CVE-2023-28531)