#VU93764 Stored cross-site scripting in Discourse - CVE-2024-35234

Vulnerability identifier: #VU93764

Vulnerability risk: Low

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

CVE-ID: CVE-2024-35234

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Discourse
Web applications / Forum & blogging software

Vendor: Civilized Discourse Construction Kit, Inc.

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 within Facebook Oneboxes. A remote attacker 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

Discourse: 3.2.0 beta1 - 3.3.0 beta2

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External links
https://github.com/discourse/discourse/security/advisories/GHSA-5chg-hm8c-wc58
https://github.com/discourse/discourse/commit/26aef0c288839378b9de5819e96eac8cf4ea60fd
https://github.com/discourse/discourse/commit/311b737c910cf0a69f61e1b8bc0b78374b6619d2

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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.