CVE-2016-1908

Publication date 15 January 2016

Last updated 25 August 2025

Ubuntu priority

Low

Why this priority?

Cvss 3 Severity Score

9.8 · Critical

Score breakdown

Description

The client in OpenSSH before 7.2 mishandles failed cookie generation for untrusted X11 forwarding and relies on the local X11 server for access-control decisions, which allows remote X11 clients to trigger a fallback and obtain trusted X11 forwarding privileges by leveraging configuration issues on this X11 server, as demonstrated by lack of the SECURITY extension on this X11 server.

Read the notes from the security team

Status

Package Ubuntu Release Status
openssh 17.04 zesty
Not affected
16.10 yakkety
Not affected
16.04 LTS xenial
Not affected
15.10 wily
Fixed 1:6.9p1-2ubuntu0.2
15.04 vivid Ignored end of life
14.04 LTS trusty
Fixed 1:6.6p1-2ubuntu2.7
12.04 LTS precise
Fixed 1:5.9p1-5ubuntu1.9

Notes

sbeattie

first patch needs to be applied before second one, which addresses the issue

mdeslaur

contrary to release not, not fixed in 7.1p2: http://lists.mindrot.org/pipermail/openssh-unix-dev/2016-January/034684.html

Patch details

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

Package Patch details
openssh

Severity score breakdown

Parameter Value
Base score 9.8 · Critical
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

Other references