CVE-2021-42096

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-10-21 · updated 2026-06-17
Weakness: CWE-307

Description

GNU Mailman before 2.1.35 may allow remote Privilege Escalation. A certain csrf_token value is derived from the admin password, and may be useful in conducting a brute-force attack against that password.

Affected products

Debian Linux: 10.0
GNU Mailman: before 2.1.35 — fixed in 2.1.35

How to fix

Upgrade to a fixed version: GNU Mailman 2.1.35. Check the vendor advisory for mitigations.

References

http://www.openwall.com/lists/oss-security/2021/10/21/4
https://bugs.launchpad.net/mailman/+bug/1947639
https://mail.python.org/archives/list/mailman-announce%40python.org/thread/IKCO6JU755AP5G5TKMBJL6IEZQTTNPDQ/
https://www.debian.org/security/2021/dsa-4991
http://www.openwall.com/lists/oss-security/2021/10/21/4
https://bugs.launchpad.net/mailman/+bug/1947639
https://mail.python.org/archives/list/mailman-announce%40python.org/thread/IKCO6JU755AP5G5TKMBJL6IEZQTTNPDQ/
https://www.debian.org/security/2021/dsa-4991

Get alerted when CVE-2021-42096 or the next vulnerability affects your stack