#VU43828 Cross-site scripting in Moodle - CVE-2011-4591

Vulnerability identifier: #VU43828

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-2011-4591

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 print_object function in lib/datalib.php in Moodle 2.0.x before 2.0.6 and 2.1.x before 2.1.3, when a developer debugging script is enabled,. 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: 2.0 - 2.0.5, 2.1 - 2.1.2

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External links
https://git.moodle.org/gw?p=moodle.git;a=commit;h=187672608ec96659e07f2461b3b83634debd16cb
https://moodle.org/mod/forum/discuss.php?d=191760
https://bugzilla.redhat.com/show_bug.cgi?id=761248

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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.