Improper neutralization of alternate XSS syntax vulnerability in The Wikimedia Foundation Mediawiki - Wikilove Extension allows Cross-Site Scripting (XSS).The issue has been remediated on the master branch, and in the release branches for MediaWiki versions 1.43, 1.44, and 1.45.
Weakness
The product does not neutralize or incorrectly neutralizes user-controlled input for alternate script syntax.
Potential Mitigations
- Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component.
- The problem of inconsistent output encodings often arises in web pages. If an encoding is not specified in an HTTP header, web browsers often guess about which encoding is being used. This can open up the browser to subtle XSS attacks.