CVE-2021-31523Public exploit

Raw-socket access via unsafe Mesa driver loading

Published Apr 21, 2021 · Updated Aug 3, 2024

Privilege escalation in Debian XScreenSaver 5.44+dfsg1-1 through 5.45+dfsg1-1 allows local users to run code with cap_net_raw. The sonar executable carries cap_net_raw, while Mesa treats it as unprivileged because its safety check compares user IDs instead of testing AT_SECURE, allowing attacker-controlled driver loading. Any local account that can launch sonar can inherit raw-socket access, which permits packet capture without root but does not by itself grant unrestricted root access.

CVSS severity7.8
High
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in Debian XScreenSaver 5.44+dfsg1-1 through 5.45+dfsg1-1 allows local users to run code with cap_net_raw. The sonar executable carries cap_net_raw, while Mesa treats it as unprivileged because its safety check compares user IDs instead of testing AT_SECURE, allowing attacker-controlled driver loading. Any local account that can launch sonar can inherit raw-socket access, which permits packet capture without root but does not by itself grant unrestricted root access.

The record

CVE
CVE-2021-31523
Published
Apr 21, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-269, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 21, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.2NIST NVDAV:L/AC:L/Au:N/C:C/I:C/A:C
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-269Improper Privilege Management
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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