Vulnerability Details : CVE-2016-2856
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.
Exploit prediction scoring system (EPSS) score for CVE-2016-2856
Probability of exploitation activity in the next 30 days: 0.18%
Percentile, the proportion of vulnerabilities that are scored at or less: ~ 55 % EPSS Score History EPSS FAQ
CVSS scores for CVE-2016-2856
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source |
---|---|---|---|---|---|
7.2
|
HIGH | AV:L/AC:L/Au:N/C:C/I:C/A:C |
3.9
|
10.0
|
NIST |
8.4
|
HIGH | CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
2.5
|
5.9
|
NIST |
CWE ids for CVE-2016-2856
-
Assigned by: nvd@nist.gov (Primary)
References for CVE-2016-2856
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http://www.halfdog.net/Security/2015/PtChownArbitraryPtsAccessViaUserNamespace/
pt_chown Arbitrary Pts Device Access via User Namespaces
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http://www.ubuntu.com/usn/USN-2985-1
USN-2985-1: GNU C Library vulnerabilities | Ubuntu security notices
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http://anonscm.debian.org/cgit/pkg-glibc/glibc.git/commit/?h=jessie&id=11475c083282c1582c4dd72eecfcb2b7d308c958
404 Not Found
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http://www.openwall.com/lists/oss-security/2016/02/23/3
oss-security - Access to /dev/pts devices via pt_chown and user namespaces
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http://www.securityfocus.com/bid/84601
GNU glibc 'pt_chown' Local Security Bypass Vulnerability
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http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-2856.html
CVE-2016-2856 in Ubuntu
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http://www.openwall.com/lists/oss-security/2016/03/07/2
oss-security - Re: Access to /dev/pts devices via pt_chown and user namespaces
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http://www.ubuntu.com/usn/USN-2985-2
USN-2985-2: GNU C Library regression | Ubuntu security notices
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http://anonscm.debian.org/cgit/pkg-glibc/glibc.git/commit/?h=jessie&id=09f7764882a81e13e7b5d87d715412283a6ce403
404 Not Found
Products affected by CVE-2016-2856
- cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:15.10:*:*:*:*:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:lts:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*