#VU49971 Stored cross-site scripting in Moodle - CVE-2021-20186
Vulnerability identifier: #VU49971
Vulnerability risk: Low
CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear]
CVE-ID: CVE-2021-20186
CWE-ID:
CWE-79
Exploitation vector: Network
Exploit availability: No
Vulnerable software:
Moodle
Web applications /
Other software
Vendor: moodle.org
Description
The disclosed vulnerability allows a remote user to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data in the TeX notation filter. A remote user can inject and execute arbitrary HTML and script code in user's browser in 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 updates from vendor's website.
Vulnerable software versions
Moodle: 3.0 - 3.0.10, 3.1.0 beta - 3.10.0, 3.2.0 beta - 3.2.9, 3.3 - 3.3.9, 3.4.0 beta - 3.4.9, 3.5.0 beta - 3.5.15, 3.6.0 beta - 3.6.10, 3.7.0 beta - 3.7.9, 3.8.0 beta - 3.8.6, 3.9.0 - 3.9.3
External links
https://moodle.org/mod/forum/discuss.php?d=417170
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
