CVE-2021-31553 Information

Description

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.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

Reference

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

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

LOW

Base Score

LOW

Base Severity

6.5