#VU79830 Stored cross-site scripting in Moodle - CVE-2023-40320

Vulnerability identifier: #VU79830

Vulnerability risk: Low

CVSSv4.0: 0.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear]

CVE-ID: CVE-2023-40320

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 passed via OAuth 2 login. 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 - 3.11.15, 3.2.0 beta - 3.2.9, 3.3 - 3.3.9, 3.4.0 beta - 3.4.9, 3.5.0 beta - 3.5.18, 3.6.0 beta - 3.6.10, 3.7.0 beta - 3.7.9, 3.8.0 beta - 3.8.9, 3.9.0 - 3.9.22, 4.0.0 - 4.0.9, 4.1.0 - 4.1.4, 4.2.0 - 4.2.1

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External links
https://moodle.org/mod/forum/discuss.php?d=449644

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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.