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Fencer Vulns
high 7.8

CVE-2016-2568 json

pkexec, when used with --user nonpriv, allows local users to escape to the parent session via a crafted TIOCSTI ioctl call, which pushes ch…

published 2017-02-13 9 y ago modified 2026-10-08 31 d ago also EUVD-2016-3642

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits
0
none known

Summary

pkexec, when used with --user nonpriv, allows local users to escape to the parent session via a crafted TIOCSTI ioctl call, which pushes characters to the terminal's input buffer.

Patch / fix

  • policykit-1 Debian 14, Debian 13 123-1

debian advisories DEBIAN-CVE-2016-2568

  • polkit Azure Linux 3.0 123-1

azure linux advisories AZL-35109

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2016-2568 updated cvss 6.1

polkit: Program run via pkexec as unprivileged user can escape to parent session via TIOCSTI ioctl

  • Red Hat Enterprise Linux 6 polkit, polkit-desktop-policy Red Hat Enterprise Linux 7 polkit
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 9 polkit, polkit-libs
    affected: no fix available

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
31 d ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
NVD 2.0 4.4 AV:L/AC:M/Au:N/C:P/I:P/A:P

Classification

Weakness
  • CWE-116 Improper Encoding or Escaping of Output

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.