CVE-2016-2856

Status: ModifiedHigh (8.4)—💥 Exploit

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

Version: 3.0
Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Base score: 8.4

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 1.03%
Percentile among all scored CVEs: 63
Score date: 10/12/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

💥 Public exploits

Exploit code or detection templates are publicly available. This is not the same as confirmed active exploitation (KEV), but it raises the risk: patch with priority.

Published on Exploit-DB · Ubuntu < 15.10 - PT Chown Arbitrary PTs Access Via User Namespace Privilege Escalation (2/22/2016)

Affected technologies (2)

Canonical — Ubuntu Linux Debian — Debian Linux

CWEs

CWE-264

References

Raw JSON (NVD)

Show

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  "lastModified": "2026-06-17T00:44:36.117",
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