Wikimedia MediaWiki Codex Special:Block Cross-Site Scripting Vulnerability

A cross-site scripting (XSS) vulnerability has been identified in the Codex Special:Block interface of Wikimedia MediaWiki. This issue arises from improper handling of input in the HTMLButtonField program file, allowing message keys to be exploited. The vulnerability affects MediaWiki versions prior to 1.39.14, as well as 1.43.4 and 1.44.1.

Impact

Exploitation of this vulnerability allows for cross-site scripting, where an attacker can inject malicious scripts that are executed in the context of the user's browser.

Reproduction

To reproduce this vulnerability, enable the Codex Special:Block interface by setting '$wgUseCodexSpecialBlock' to true. Then, access the Codex Special:Block page with the 'uselang=x-xss' parameter. A popup will indicate that the 'ipbsubmit' message is not properly escaped, demonstrating the XSS vulnerability.

Remediation

Users can update to MediaWiki versions 1.39.14, 1.43.4, or 1.44.1, where this vulnerability has been addressed.