CVE Feed

    Dashboard / CVE / CVE-2021-31553

    CVE-2021-31553

    An issue was discovered in the CheckUser extension for MediaWiki through 1.35.2. MediaWiki usernames with trailing whitespace could be stored in the cu_log database table such that denial of service occurred for certain CheckUser extension pages and functionality. For example, the attacker could turn off Special:CheckUserLog and thus interfere with usage tracking.

    Published:Apr 22, 2021
    Last Modified:Nov 21, 2024
    EPS:Apr 22, 2021
    EPSS Score:0.0073
    CVSS Score:6.5

    Affected Products

    Vendor
    Mediawiki
    Product
    Mediawiki

    Exploits

    No exploit reference

    Common Weakness Enumeration

    CWE-428 Unquoted Search Path or Element

    Common Attack Pattern Enumeration and Classification (CAPEC)

    No CAPEC recorded yet

    Related CVEs

    CVE-2026-34095 (CVSS 0) — Vulnerability in Wikimedia Foundation MediaWiki. This vulnerability is associated with program files include…
    CVE-2026-34094 (CVSS 2) — Vulnerability in Wikimedia Foundation MediaWiki. This vulnerability is associated with program files include…
    CVE-2026-34093 (CVSS 1.1) — Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki. …
    CVE-2026-34092 (CVSS 2.1) — Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki. …
    CVE-2026-34091 (CVSS 5.5) — Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki. T…
    CVE-2026-34088 (CVSS 1.3) — Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki. T…
    CVE-2026-34087 (CVSS 5.1) — Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation OATHAuth. Th…
    CVE-2025-67481 (CVSS 0) — Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in W…
    CVE-2025-67483 (CVSS 0) — Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in W…
    CVE-2025-67484 (CVSS 0) — Vulnerability in Wikimedia Foundation MediaWiki. This vulnerability is associated with program files includes/…

    References

    https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/666963
    https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/666964
    https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667023
    https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667024
    https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667025
    https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667027
    https://phabricator.wikimedia.org/T275669
    https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/666963
    https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/666964
    https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667023
    https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667024
    https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667025
    https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667027
    https://phabricator.wikimedia.org/T275669

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High