CVE-2021-42040 Denial of service in n/a
An attacker can cause a denial of service by triggering an infinite loop in the MediaWiki Loops extension, leading to memory exhaustion.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-42040?
CVE-2021-42040 is a high-severity denial of service vulnerability in Mediawiki Mediawiki, published on 6 Oct 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 MediaWiki through 1.36.2. A parser function related to loop control allowed for an infinite loop (and php-fpm hang) within the Loops extension because egLoopsCountLimit is mishandled. This could lead to memory exhaustion.
Weakness: CWE-835
Which versions are affected by CVE-2021-42040?
1 open source package ship an affected version, including mediawiki. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
mediawiki Bitnami | All versions | 1.36.3 |
Products include Mediawiki Mediawiki.
How do I fix CVE-2021-42040?
Upgrade mediawiki to 1.36.3 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-2021-42040 being exploited?
There is no known exploitation of CVE-2021-42040 in the wild and no public exploit code.
Other vulnerabilities in Mediawiki Mediawiki
Sources
Also known as BIT-mediawiki-2021-42040, GHSA-qrm9-mhjr-qfm7, UBUNTU-CVE-2021-42040.