Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Canonical | Ubuntu Linux | 12.04 |
| Debian | Debian Linux | 8.0 |
| Gnu | Glibc | <= 2.18 |
Related Weaknesses (CWE)
References
- http://anonscm.debian.org/cgit/pkg-glibc/glibc.git/commit/?h=jessie&id=09f776488
- http://anonscm.debian.org/cgit/pkg-glibc/glibc.git/commit/?h=jessie&id=11475c083
- 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
- http://anonscm.debian.org/cgit/pkg-glibc/glibc.git/commit/?h=jessie&id=09f776488
- http://anonscm.debian.org/cgit/pkg-glibc/glibc.git/commit/?h=jessie&id=11475c083
- 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
FAQ
What is CVE-2016-2856?
CVE-2016-2856 is a vulnerability with a CVSS score of 8.4 (HIGH). 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 packa...
How severe is CVE-2016-2856?
CVE-2016-2856 has been rated HIGH with a CVSS base score of 8.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2016-2856?
Check the references section above for vendor advisories and patch information. Affected products include: Canonical Ubuntu Linux, Debian Debian Linux, Gnu Glibc.