#VU43873 Cross-site scripting in Moodle - CVE-2011-4286

Vulnerability identifier: #VU43873

Vulnerability risk: Low

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2011-4286

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Moodle
Web applications / Other software

Vendor: moodle.org

Description

Vulnerability allows a remote attacker to perform XSS attacks.

The vulnerability is caused by an input validation error in the media-filter implementation in filter/mediaplugin/filter.php in Moodle 1.9.x before 1.9.11 and 2.0.x before 2.0.2 when processing vectors involving (1) Flash Video (aka FLV) files and (2) YouTube videos. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in victim's browser in security context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Moodle: 1.9 - 1.9.10, 2.0 - 2.0.1

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External links
https://git.moodle.org/gw?p=moodle.git;a=commit;h=8f81bfd412c6b2e93a5b15711727d5cb7cc78336
https://moodle.org/mod/forum/discuss.php?d=170012
https://openwall.com/lists/oss-security/2011/11/14/1

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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.