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Fencer Intel
medium 4.3

CVE-2021-42096 json

GNU Mailman before 2.1.35 may allow remote Privilege Escalation.

published 5y ago modified 4mo ago also EUVD-2021-29082

cvss
4.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 69%
public exploits
0
none known

Summary

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.

Patch / fix

  • gnu mailman 2.1.35
  • mailman Ubuntu 18.04 LTS 1:2.1.26-1ubuntu0.4
  • mailman Ubuntu 20.04 LTS 1:2.1.29-1ubuntu3.1
  • mailman Ubuntu Pro 16.04 LTS 1:2.1.20-1ubuntu0.6+esm1

ubuntu advisories UBUNTU-CVE-2021-42096

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

  • mailman RHEL 8 3:2.1.29-12.module+el8.5.0+13211+e8845b76.1
  • mailman RHEL 8.1 EUS 3:2.1.29-4.module+el8.1.0+13242+45286865.1
  • mailman RHEL 8.2 EUS 3:2.1.29-4.module+el8.2.0+13241+705a6aa4.3
  • mailman RHEL 8.4 EUS 3:2.1.29-11.module+el8.4.0+13212+81332387.1

red hat advisories RHSA-2021:4838RHSA-2021:4837RHSA-2021:4839RHSA-2021:4826

  • mailman SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +10 more 2.1.17-3.26.1

suse advisories SUSE-SU-2022:1886-1

  • mailman Package Hub 15 SP2 2.1.35-bp152.7.6.1
  • mailman openSUSE Leap 15.2 2.1.35-lp152.7.6.1

opensuse advisories openSUSE-SU-2021:1452-1openSUSE-SU-2021:1436-1

  • mailman AlmaLinux 8 3:2.1.29-12.module_el8.5.0+26+48d4c9ee.2
  • mailman AlmaLinux 8 3:2.1.29-12.module_el8.5.0+2601+e8845b76.1
  • mailman AlmaLinux 8 3:2.1.29-12.module_el8.5.0+2602+327eb9f3.2

almalinux advisories ALSA-2021:4826

  • mailman Rocky Linux 8 3:2.1.29-12.module+el8.5.0+717+27fd1ba7.2
  • mailman Rocky Linux 8 3:2.1.29-12.module+el8.5.0+703+19300c10

rocky linux advisories RLSA-2021:4826

Is CVE-2021-42096 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-42096 updated cvss 4.3

mailman: CSRF token derived from admin password allows offline brute-force attack

  • Red Hat Enterprise Linux AppStream (v. 8) mailman 2.1.29-12.module+el8.5.0+13211+e8845b76.1
    fixed: vendor fix RHSA-2021:4826
  • Red Hat Enterprise Linux AppStream EUS (v. 8.1) mailman 2.1.29-4.module+el8.1.0+13242+45286865.1
    fixed: vendor fix RHSA-2021:4838
  • Red Hat Enterprise Linux AppStream EUS (v. 8.2) mailman 2.1.29-4.module+el8.2.0+13241+705a6aa4.3
    fixed: vendor fix RHSA-2021:4837
  • Red Hat Enterprise Linux AppStream EUS (v.8.4) mailman 2.1.29-11.module+el8.4.0+13212+81332387.1
    fixed: vendor fix RHSA-2021:4839
  • Red Hat Enterprise Linux 6 mailman Red Hat Enterprise Linux 7 mailman
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.25% chance of exploitation in the next 30 days, higher than 69% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
NVD 2.0 4.0 AV:N/AC:L/Au:S/C:P/I:N/A:N

Classification

Weakness
  • CWE-307 Improper Restriction of Excessive Authentication Attempts

References

Sources

Fencer Intel 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.