Cross-site scripting (XSS) vulnerability in MediaWiki before 1.16.5, when Internet Explorer 6 or earlier is used, allows remote attackers to inject arbitrary web script or HTML via an uploaded file accessed with a dangerous extension such as .shtml at the end of the query string, in conjunction with a modified URI path that has a %2E sequence in place of the . (dot) character. NOTE: this vulnerability exists because of an incomplete fix for CVE-2011-1578 and CVE-2011-1587.

MediaWiki 1.16.5 was released to correct two security flaws :

The first issue is yet another recurrence of the Internet Explorer 6 XSS vulnerability that caused the release of 1.16.4. It was pointed out that there are dangerous extensions with more than four characters, so the regular expressions we introduced had to be updated to match longer extensions. (CVE-2011-1765)

The second issue allows unauthenticated users to gain additional rights, on wikis where $wgBlockDisablesLogin is enabled. By default, it is disabled. The issue occurs when a malicious user sends cookies which contain the user name and user ID of a 'victim' account. In certain circumstances, the rights of the victim are loaded and persist throughout the malicious request, allowing the malicious user to perform actions with the victim's rights. (CVE-2011-1766)

$wgBlockDisablesLogin is a feature which is sometimes used on private wikis to prevent users who have an account from logging in and viewing content on the wiki.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
54609	Fedora 13 : mediawiki-1.16.5-59.fc13 (2011-6775)	Nessus	Fedora Local Security Checks	medium
54608	Fedora 14 : mediawiki-1.16.5-59.fc14 (2011-6774)	Nessus	Fedora Local Security Checks	medium
54572	Fedora 15 : mediawiki-1.16.5-59.fc15 (2011-6781)	Nessus	Fedora Local Security Checks	medium

Detections

Analytics

CVE-2011-1765

medium

Tenable Plugins

medium

medium

medium