=========================================================================Ubuntu Security Notice USN-3276-1
May 05, 2017

shadow vulnerabilities
=========================================================================
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:

su could be made to crash or stop programs as an administrator.

Software Description:
- shadow: system login tools

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                           1:4.2-3.2ubuntu1.17.04.1
  passwd                          1:4.2-3.2ubuntu1.17.04.1
  uidmap                          1:4.2-3.2ubuntu1.17.04.1

Ubuntu 16.10:
  login                           1:4.2-3.2ubuntu1.16.10.1
  passwd                          1:4.2-3.2ubuntu1.16.10.1
  uidmap                          1:4.2-3.2ubuntu1.16.10.1

Ubuntu 16.04 LTS:
  login                           1:4.2-3.1ubuntu5.2
  passwd                          1:4.2-3.1ubuntu5.2
  uidmap                          1:4.2-3.1ubuntu5.2

Ubuntu 14.04 LTS:
  login                           1:4.1.5.1-1ubuntu9.4
  passwd                          1:4.1.5.1-1ubuntu9.4
  uidmap                          1:4.1.5.1-1ubuntu9.4

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

References:
  https://ubuntu.com/security/notices/USN-3276-1
  CVE-2016-6252, CVE-2017-2616

Package Information:
  https://launchpad.net/ubuntu/+source/shadow/1:4.2-3.2ubuntu1.17.04.1
  https://launchpad.net/ubuntu/+source/shadow/1:4.2-3.2ubuntu1.16.10.1
  https://launchpad.net/ubuntu/+source/shadow/1:4.2-3.1ubuntu5.2
  https://launchpad.net/ubuntu/+source/shadow/1:4.1.5.1-1ubuntu9.4