CVE-2016-2856: Canonical Ubuntu Linux

High severity, CVSS 8.4. EPSS: 1% chance of exploitation in the next 30 days.

pt_chown in the glibc package before 2.19-18+deb8u4 on Debian jessie; the elibc package before 2.15-0ubuntu10.14 on Ubuntu 12.04 LTS and before 2.19-0ubuntu6.8 on Ubuntu 14.04 LTS; and the glibc package before 2.21-0ubuntu4.2 on Ubuntu 15.10 and before 2.23-0ubuntu1 on Ubuntu 16.04 LTS and 16.10 lacks a namespace check associated with file-descriptor passing, which allows local users to capture keystrokes and spoof data, and possibly gain privileges, via pts read and write operations, related to debian/sysdeps/linux.mk. NOTE: this is not considered a vulnerability in the upstream GNU C Library because the upstream documentation has a clear security recommendation against the --enable-pt_chown option.

Affected products

• Canonical Ubuntu Linux: version 12.04 only; version 14.04 only; version 15.10 only
• Debian Debian Linux: version 8.0 only

Published 2016-03-14. Last modified 2026-06-17.