CVE-2020-14145

Published: 29 June 2020

The client side in OpenSSH 5.7 through 8.4 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts (where no host key for the server has been cached by the client).

Priority

Low

CVSS 3 base score: 5.9

Status

Package Release Status
openssh
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 21.04 (Hirsute Hippo) Needed

Ubuntu 20.10 (Groovy Gorilla) Needed

Ubuntu 20.04 LTS (Focal Fossa) Needed

Ubuntu 18.04 LTS (Bionic Beaver) Needed

Ubuntu 16.04 ESM (Xenial Xerus) Needed

Ubuntu 14.04 ESM (Trusty Tahr) Needed

Patches:
Upstream: https://anongit.mindrot.org/openssh.git/commit/?id=b3855ff053f5078ec3d3c653cdaedefaa5fc362d
openssh-ssh1
Launchpad, Ubuntu, Debian
Upstream Ignored
(frozen on openssh 7.5p)
Ubuntu 21.04 (Hirsute Hippo) Needed

Ubuntu 20.10 (Groovy Gorilla) Needed

Ubuntu 20.04 LTS (Focal Fossa) Needed

Ubuntu 18.04 LTS (Bionic Beaver) Needed

Ubuntu 16.04 ESM (Xenial Xerus) Does not exist

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Notes

AuthorNote
seth-arnold
openssh-ssh1 is provided for compatibility with old devices that
cannot be upgraded to modern protocols. Thus we may not provide security
support for this package if doing so would prevent access to equipment.
mdeslaur
Per the advisory, "The developers of OpenSSH are not planning to
change the behavior of OpenSSH regarding this issue"
We will not be releasing updates for Ubuntu for this issue.

On 2020-12-02, it was announced that a partial mitigation has
been commited by OpenSSH developers:
https://www.openwall.com/lists/oss-security/2020/12/02/1
sbeattie
partial mitigation landed in openssh 8.4p1

References