CVE-2016-2856

HIGH

Description

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.

References

http://anonscm.debian.org/cgit/pkg-glibc/glibc.git/commit/?h=jessie&id=09f7764882a81e13e7b5d87d715412283a6ce403

http://anonscm.debian.org/cgit/pkg-glibc/glibc.git/commit/?h=jessie&id=11475c083282c1582c4dd72eecfcb2b7d308c958

http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-2856.html

http://www.halfdog.net/Security/2015/PtChownArbitraryPtsAccessViaUserNamespace/

http://www.openwall.com/lists/oss-security/2016/02/23/3

http://www.openwall.com/lists/oss-security/2016/03/07/2

http://www.securityfocus.com/bid/84601

http://www.ubuntu.com/usn/USN-2985-1

http://www.ubuntu.com/usn/USN-2985-2

Details

Source: MITRE

Published: 2016-03-14

Updated: 2016-11-28

Type: CWE-264

Risk Information

CVSS v2.0

Base Score: 7.2

Vector: (AV:L/AC:L/Au:N/C:C/I:C/A:C)

Impact Score: 10

Exploitability Score: 3.9

Severity: HIGH

CVSS v3.0

Base Score: 8.4

Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Impact Score: 5.9

Exploitability Score: 2.5

Severity: HIGH