#VU89213 Improper access control in MediaWiki - CVE-2024-34502

Vulnerability identifier: #VU89213

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2024-34502

CWE-ID: CWE-284

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
MediaWiki
Web applications / CMS

Vendor: MediaWiki.org

Description

The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists in the WikibaseLexeme extension due to Special:MergeLexemes makes edits on GET requests without edit tokens. A remote attacker can make an edit that merges the from-id to the to-id, even if the request was not a POST request, and even if it does not contain an edit token.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

MediaWiki: 1.39.0 rc.0 - 1.39.6, 1.40.0 rc.0 - 1.41.0

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External links
https://phabricator.wikimedia.org/T357101
https://gerrit.wikimedia.org/r/c/mediawiki/extensions/WikibaseLexeme/+/1013359
https://gerrit.wikimedia.org/r/q/Iae0c7c3b979118559c9ce2276618c6cdec11e63d

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.