CVE-2021-30158Public exploitNetwork attack vector

Watchlist disclosure via blocked token-reset denial

Published Apr 6, 2021 · Updated Aug 3, 2024

Improper authentication in MediaWiki before 1.31.12 and 1.32.0 through 1.35.1 allows remote attackers to read private watchlists. SpecialResetTokens inherits FormSpecialPage's default block restriction, so a block notice replaces the reset form instead of invalidating compromised watchlist tokens. Exploitation requires prior possession of a user's watchlist token and remains limited to continued feed access while the account is blocked.

CVSS severity5.3
Medium
EPSS probability1.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in MediaWiki before 1.31.12 and 1.32.0 through 1.35.1 allows remote attackers to read private watchlists. SpecialResetTokens inherits FormSpecialPage's default block restriction, so a block notice replaces the reset form instead of invalidating compromised watchlist tokens. Exploitation requires prior possession of a user's watchlist token and remains limited to continued feed access while the account is blocked.

The record

CVE
CVE-2021-30158
Published
Apr 6, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-287, T1213
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 6, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-287Improper Authentication
T1213Data from Information Repositories

Public exploit references

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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