#VU51477 Stored cross-site scripting in Moodle - CVE-2021-20280
Published: March 15, 2021
Vulnerability identifier: #VU51477
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green
CVE-ID: CVE-2021-20280
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Moodle
Moodle
Software vendor:
moodle.org
moodle.org
Description
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data passed via feedback answer. A remote attacker can permanently inject and execute arbitrary HTML and script code in user's browser in context of vulnerable website. Note, blind SSRF attack vector is also possible in this case.
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.
Remediation
Install updates from vendor's website.