CVE-2021-31523

The Debian xscreensaver 5.42+dfsg1-1 package for XScreenSaver has cap_net_raw enabled for the ...

7.8 HighFix available

The Debian xscreensaver 5.42+dfsg1-1 package for XScreenSaver has cap_net_raw enabled for the /usr/libexec/xscreensaver/sonar file, which allows local users to gain privileges because this is arguably incompatible with the design of the Mesa 3D Graphics library dependency.

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.32%Unchanged since Apr 27, 2021

What each source reports

NVD Score used 7.8

Record: CVE-2021-31523
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0: 7.2 HighAV:L/AC:L/Au:N/C:C/I:C/A:C
Weakness: CWE-269
Updated: 2026-11-02

CVE List No score

Record: CVE-2021-31523
Updated: 2026-11-02

EUVDEUVD-2021-18422 No score

Record: EUVD-2021-18422
Updated: 2026-11-03

GitHub AdvisoriesGHSA-74g6-fv7f-g2hq No score

The Debian xscreensaver 5.42+dfsg1-1 package for XScreenSaver has cap_net_raw enabled for the ...

Record: GHSA-74g6-fv7f-g2hq
Weakness: CWE-269
Updated: 2026-11-02

OSV 7.8

Record: CVE-2021-31523
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2021-31523 7.8

Record: DEBIAN-CVE-2021-31523
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2021-31523 7.8

Record: UBUNTU-CVE-2021-31523
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

Affected products

xscreensaver project xscreensaver

Affected packages

Affected packages
Package	Affected	Fixed
`xscreensaver` Debian:12	before 5.45+dfsg1-2	5.45+dfsg1-2
`xscreensaver` Debian:13	before 5.45+dfsg1-2	5.45+dfsg1-2
`xscreensaver` Debian:14	before 5.45+dfsg1-2	5.45+dfsg1-2
`xscreensaver` Ubuntu:16.04:LTS	All versions, plus listed versions 5.30-1ubuntu15.34-1ubuntu15.34-2ubuntu1	None known
`xscreensaver` Ubuntu:18.04:LTS	All versions, plus listed versions 5.36-1ubuntu1	None known
`xscreensaver` Ubuntu:20.04:LTS	All versions, plus listed versions 5.42+dfsg1-1ubuntu1	None known
`xscreensaver` Ubuntu:22.04:LTS	All versions, plus listed versions 5.45+dfsg1-2ubuntu1	None known
`xscreensaver` Ubuntu:24.04:LTS	All versions, plus listed versions 6.02+dfsg1-2ubuntu26.06+dfsg1-3ubuntu16.08+dfsg1-1ubuntu16.08+dfsg1-1ubuntu26.08+dfsg1-1ubuntu3	None known
`xscreensaver` Ubuntu:25.10	All versions, plus listed versions 6.08+dfsg1-1ubuntu36.08+dfsg1-1ubuntu4	None known
`xscreensaver` Ubuntu:26.10	All versions, plus listed versions 6.08+dfsg1-1ubuntu5	None known
`xscreensaver` Ubuntu:26.04:LTS	All versions, plus listed versions 6.08+dfsg1-1ubuntu46.08+dfsg1-1ubuntu5	None known

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-31523 is a high vulnerability (CVSS 7.8) in Xscreensaver Project Xscreensaver, published April 21, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.32%, the 24th percentile. Fixed in xscreensaver 5.45+dfsg1-2.