USN-2966-1: OpenSSH vulnerabilities

Releases

• Ubuntu 15.10
• Ubuntu 14.04 ESM
• Ubuntu 12.04

Packages

• openssh - secure shell (SSH) for secure access to remote machines

Details

Shayan Sadigh discovered that OpenSSH incorrectly handled environment files
when the UseLogin feature is enabled. A local attacker could use this issue
to gain privileges. (CVE-2015-8325)

Ben Hawkes discovered that OpenSSH incorrectly handled certain network
traffic. A remote attacker could possibly use this issue to cause OpenSSH
to crash, resulting in a denial of service. This issue only applied to
Ubuntu 15.10. (CVE-2016-1907)

Thomas Hoger discovered that OpenSSH incorrectly handled untrusted X11
forwarding when the SECURITY extension is disabled. A connection configured
as being untrusted could get switched to trusted in certain scenarios,
contrary to expectations. (CVE-2016-1908)

It was discovered that OpenSSH incorrectly handled certain X11 forwarding
data. A remote authenticated attacker could possibly use this issue to
bypass certain intended command restrictions. (CVE-2016-3115)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 15.10

• openssh-server - 1:6.9p1-2ubuntu0.2

Ubuntu 14.04

• openssh-server - 1:6.6p1-2ubuntu2.7

Ubuntu 12.04

• openssh-server - 1:5.9p1-5ubuntu1.9

In general, a standard system update will make all the necessary changes.

References

• CVE-2015-8325
• CVE-2016-1907
• CVE-2016-1908
• CVE-2016-3115