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OpenAdvisories
Medium USN-6561-1 1 CVE

libssh vulnerability

Published Dec 19, 2023 · Updated Apr 27, 2026

Ecosystem: Ubuntu

Summary

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.

Fixed packages 2

ReleasePackageFixed in
Ubuntu · 20.04 LTS 20.04:LTS libssh 0.9.3-2ubuntu2.4
Ubuntu · 22.04 LTS 22.04:LTS libssh 0.9.6-2ubuntu0.22.04.2

Vulnerabilities 1

  • Medium 5.9
    CVE-2023-48795 Public exploit Scanner template EPSS 94%

    Prefix Truncation Attack against ChaCha20-Poly1305 and Encrypt-then-MAC aka Terrapin

    The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server…

    zot kubescape kots k3d Debian Ubuntu Azure Linux Alpine Wolfi PyPI Go crates.io

References

  • report
    https://ubuntu.com/security/CVE-2023-48795