CVE-2021-31553
MEDIUMCVSS 6.5/10EPSS 1.40%
Last modified
CVE-2021-31553 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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. EPSS estimates a 1.40% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Mediawiki | Mediawiki | <= 1.35.2 |
References
- https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/666963Issue Tracking, Third Party Advisory
- https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/666964Issue Tracking, Third Party Advisory
- https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667023Issue Tracking, Third Party Advisory
- https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667024Issue Tracking, Third Party Advisory
- https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667025Issue Tracking, Third Party Advisory
- https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667027Issue Tracking, Third Party Advisory
- https://phabricator.wikimedia.org/T275669Third Party Advisory
- https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/666963Issue Tracking, Third Party Advisory
- https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/666964Issue Tracking, Third Party Advisory
- https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667023Issue Tracking, Third Party Advisory
- https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667024Issue Tracking, Third Party Advisory
- https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667025Issue Tracking, Third Party Advisory
- https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/667027Issue Tracking, Third Party Advisory
- https://phabricator.wikimedia.org/T275669Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is 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.
How severe is CVE-2021-31553?
CVE-2021-31553 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 1.40% probability of exploitation in the next 30 days.
How do I fix CVE-2021-31553?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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Are you affected by CVE-2021-31553?
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Scan your code nowSource: NVD / NIST