The do_setup_env function in session.c in sshd in OpenSSH through 7.2p2, when the UseLogin feature is enabled and PAM is configured to read .pam_environment files in user home directories, allows local users to gain privileges by triggering a crafted environment for the /bin/login program, as demonstrated by an LD_PRELOAD environment variable.

Affected: Ubuntu:14.04:LTS: openssh

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)