CVE-2021-42097

Severity: high (CVSS 8.0 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-352

Description

GNU Mailman before 2.1.35 may allow remote Privilege Escalation. A csrf_token value is not specific to a single user account. An attacker can obtain a value within the context of an unprivileged user account, and then use that value in a CSRF attack against an admin (e.g., for account takeover).

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/1947640
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/1947640
https://mail.python.org/archives/list/mailman-announce%40python.org/thread/IKCO6JU755AP5G5TKMBJL6IEZQTTNPDQ/
https://www.debian.org/security/2021/dsa-4991

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