CVE-2021-42096Network attack vector

List administrator password disclosure via password-derived CSRF token

Published Oct 21, 2021 · Updated Aug 4, 2024

Information disclosure in GNU Mailman before 2.1.35 allows remote authenticated users to recover a list administrator password. The CSRFcheck.py csrf_token() function places a SHA-1 value derived from the list administrator password and issuance time in a hidden form field. List membership is required; the exposed value supports offline password guessing and subsequent administrative access.

CVSS severity4.3
Medium
EPSS probability1.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in GNU Mailman before 2.1.35 allows remote authenticated users to recover a list administrator password. The CSRFcheck.py csrf_token() function places a SHA-1 value derived from the list administrator password and issuance time in a hidden form field. List membership is required; the exposed value supports offline password guessing and subsequent administrative access.

The record

CVE
CVE-2021-42096
Published
Oct 21, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-307, T1110.002
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 21, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
4.0NIST NVDAV:N/AC:L/Au:S/C:P/I:N/A:N

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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-307Improper Restriction of Excessive Authentication Attempts
T1110.002Brute Force: Password Cracking

Public exploit references

No public exploit references are available in this record.

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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