USN-3276-2: shadow regression

17 May 2017

shadow regression

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 17.04
  • Ubuntu 16.10
  • Ubuntu 16.04 LTS
  • Ubuntu 14.04 LTS

Summary

USN-3276-1 introduced a regression in su.

Software Description

  • shadow - system login tools

Details

USN-3276-1 intended to fix a vulnerability in su. The solution introduced a regression in su signal handling. This update modifies the security fix. We apologize for the inconvenience.

Original advisory details:

Sebastian Krahmer discovered integer overflows in shadow utilities. A local attacker could possibly cause them to crash or potentially gain privileges via crafted input. (CVE-2016-6252)

Tobias Stöckmann discovered a race condition in su. A local attacker could cause su to send SIGKILL to other processes with root privileges. (CVE-2017-2616)

Update instructions

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

Ubuntu 17.04
login - 1:4.2-3.2ubuntu1.17.04.2
passwd - 1:4.2-3.2ubuntu1.17.04.2
uidmap - 1:4.2-3.2ubuntu1.17.04.2
Ubuntu 16.10
login - 1:4.2-3.2ubuntu1.16.10.2
passwd - 1:4.2-3.2ubuntu1.16.10.2
uidmap - 1:4.2-3.2ubuntu1.16.10.2
Ubuntu 16.04 LTS
login - 1:4.2-3.1ubuntu5.3
passwd - 1:4.2-3.1ubuntu5.3
uidmap - 1:4.2-3.1ubuntu5.3
Ubuntu 14.04 LTS
login - 1:4.1.5.1-1ubuntu9.5
passwd - 1:4.1.5.1-1ubuntu9.5
uidmap - 1:4.1.5.1-1ubuntu9.5

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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

References