CVE-2021-40347 json
GNU Mailman Postorius Access Control Issues
published 2021-09-10 5 y ago modified 2026-06-17 4 mo ago also GHSA-v83x-78q3-gr2j , PYSEC-2021-319 , EUVD-2021-0197
- cvss
- 5.4
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.2%
- EPSS 1.2% chance of exploitation in 30 days, percentile 68%
- public exploits
- 0
- none known
Summary
An issue was discovered in views/list.py in GNU Mailman Postorius before 1.3.5. An attacker (logged into any account) can send a crafted POST request to unsubscribe any user from a mailing list, also revealing whether that address was subscribed in the first place.
Patch / fix
- pypi postorius 1.3.5
- postorius_project postorius 1.3.5
- postorius Debian 14, Debian 13, Debian 12 1.3.5-1
debian advisories DEBIAN-CVE-2021-40347
- postorius Ubuntu 18.04 LTS 1.1.2-3ubuntu0.1
- postorius Ubuntu 20.04 LTS 1.2.4-1ubuntu0.1
- postorius Ubuntu 22.04 LTS 1.3.5-1
ubuntu advisories UBUNTU-CVE-2021-40347
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- postorius Arch Linux 1.3.5-1
arch linux advisories AVG-2375
Exploit prediction
1.21% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- gitlab.com https://gitlab.com/mailman/postorius/-/issues/531 referenced PoC, tagged "exploit" by a source, unverified
- phabricator.wikimedia.org https://phabricator.wikimedia.org/T289798 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
| NVD | 2.0 | 5.5 | AV:N/AC:L/Au:S/C:P/I:P/A:N |
| GitHub | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | postorius | <1.3.5 |
1.3.5 |
Classification
- Weakness
-
- CWE-284 Improper Access Control
References
-
gitlab.com
/mailman/postorius/-/commit/3d880c56b58bc26b32eac0799407d74b64b7474b
web, patch, third-party-advisory
-
gitlab.com
/mailman/postorius/-/issues/531
web, exploit, issue-tracking, patch, third-party-advisory
-
phabricator.wikimedia.org
/T289798
web, exploit, patch, third-party-advisory
-
debian.org
/security/2021/dsa-4970
vendor-advisory, web, third-party-advisory, advisory
-
gitlab.com
/mailman/postorius/-/tags
web, third-party-advisory
-
bugs.debian.org
/cgi-bin/bugreport.cgi?bug=993746
web, mailing-list, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-40347
advisory
-
github.com
/pypa/advisory-database/tree/main/vulns/postorius/PYSEC-2021-319.yaml
web
-
gitlab.com
/mailman/postorius
package
-
github.com
/advisories/GHSA-v83x-78q3-gr2j
advisory
Sources
- CVE List CVE-2021-40347
- GitHub Advisory GHSA-v83x-78q3-gr2j
- NVD CVE-2021-40347
- OSV PYSEC-2021-319
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.