Vulnerability identifier: #VU54645

Vulnerability risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-36128

CWE-ID: CWE-287

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
MediaWiki
Web applications / CMS

Vendor: MediaWiki.org

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to the Autoblocks for CentralAuth-issued suppression blocks are not properly implemented. A remote attacker can bypass authentication process and gain unauthorized access to the application.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

MediaWiki: 1.36.0, 1.31.0 - 1.31.14, 1.35.0 - 1.35.2

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External links
http://gerrit.wikimedia.org/r/q/I3e65690695313380c798b62edfda726b6e374f89
http://gerrit.wikimedia.org/r/q/I15d14c88a1e30df92c470bc191c4ee573172d4d1
http://phabricator.wikimedia.org/T281972

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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.