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…
- 8.4HighCVSS base score
- 1.0%Exploitation in 30 daysEPSS · top 36% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- 1Public exploitsMetasploit, Nuclei and Exploit-DB
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. The public collections list an Exploit-DB entry for it.
Show the exploits1
Exploit-DB1 entry
- Ubuntu < 15.10 - PT Chown Arbitrary PTs Access Via User Namespace Privilege Escalation (Exploit-DB entry) (opens in a new tab)
EDB-ID 41760local, linuxpublished 22 Feb 2016Not verified
Modules, templates and exploits as listed by the Metasploit Framework (BSD-3-Clause), ProjectDiscovery's Nuclei templates (MIT) and the Exploit Database (GPLv2), read once a day. Where the data comes from
Timeline
ID reserved
By mitre
- 8 days later
· 8 days later
Published
- 8 years later
· 8 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.0 | High8.4 | CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 1.0% · top 36% of all CVEs (10 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.4.
Affected products
n/a
- affected n/a
References
9
- http://www.halfdog.net/Security/2015/PtChownArbitraryPtsAccessViaUserNamespace/ (opens in a new tab)x_refsource_MISCx_transferred
- http://anonscm.debian.org/cgit/pkg-glibc/glibc.git/commit/?h=jessie&id=11475c083282c1582c4dd72eecfcb2b7d308c958 (opens in a new tab)x_refsource_CONFIRMx_transferred
- [oss-security] 20160306 Re: Access to /dev/pts devices via pt_chown and user namespaces (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- 84601 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
- USN-2985-2 (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
- http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-2856.html (opens in a new tab)x_refsource_CONFIRMx_transferred
- http://anonscm.debian.org/cgit/pkg-glibc/glibc.git/commit/?h=jessie&id=09f7764882a81e13e7b5d87d715412283a6ce403 (opens in a new tab)x_refsource_CONFIRMx_transferred
- [oss-security] 20160223 Access to /dev/pts devices via pt_chown and user namespaces (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- USN-2985-1 (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2016-3929 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2016-2856)Record last updated .