CVE-2021-31553 Denial of service in n/a
Attackers can cause denial of service in MediaWiki CheckUser extension by storing usernames with trailing whitespace, disrupting usage tracking.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-31553?
CVE-2021-31553 is a medium-severity denial of service vulnerability in Mediawiki Mediawiki, published on 22 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-428
Which versions are affected by CVE-2021-31553?
1 open source package ship an affected version, including mediawiki. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
mediawiki Bitnami | All versions | 1.35.3 |
Products include Mediawiki Mediawiki.
How do I fix CVE-2021-31553?
Upgrade mediawiki to 1.35.3 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-31553 being exploited?
There is no known exploitation of CVE-2021-31553 in the wild and no public exploit code.
Other vulnerabilities in Mediawiki Mediawiki
Sources
Also known as BIT-mediawiki-2021-31553, GHSA-6475-q4qm-387r.