#VU52573 Information disclosure in MediaWiki - CVE-2021-31549

Vulnerability identifier: #VU52573

Vulnerability risk: Low

CVSSv4.0: 1.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-31549

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
MediaWiki
Web applications / CMS

Vendor: MediaWiki.org

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to excessive data output by the application in the AbuseFilter extension. A remote authenticated attacker can use the Special:AbuseFilter/examine form to disclose the suppressed MediaWiki usernames.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

MediaWiki: 1.31.0 - 1.35.1

---

External links
https://lists.wikimedia.org/pipermail/mediawiki-announce/2021-April/000274.html
https://phabricator.wikimedia.org/T274152
https://gerrit.wikimedia.org/r/q/I71a6d521bd12931ce60eec4d2dc35af19146000f
https://gerrit.wikimedia.org/r/q/I6063c02fa261c4cc0e6dbbb2db4e111eb85912c2

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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