#VU52553 Exposure of Resource to Wrong Sphere in MediaWiki - CVE-2021-31548

Vulnerability identifier: #VU52553

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-31548

CWE-ID: N/A

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
MediaWiki
Web applications / CMS

Vendor: MediaWiki.org

Description

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to exposure of resource to wrong sphere issue in the AbuseFilter extension. A remote authenticated attacker can bypass AbuseFilter and have their edits completed.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

MediaWiki: 1.31.0 - 1.35.1

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External links
https://lists.wikimedia.org/pipermail/mediawiki-announce/2021-April/000274.html
https://phabricator.wikimedia.org/T272333
https://gerrit.wikimedia.org/r/q/Ifac795125927d584a31d95e1b4c4241eef860fa1

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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.