#VU41200 Cross-site scripting in vBulletin - CVE-2014-2021

Vulnerability identifier: #VU41200

Vulnerability risk: Low

CVSSv4.0: 5.5 [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:P/U:Clear]

CVE-ID: CVE-2014-2021

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
vBulletin
Web applications / Forum & blogging software

Vendor: vBulletin

Description

Vulnerability allows a remote attacker to perform Cross-site scripting attacks.

An input validation error exists in admincp/apilog.php in vBulletin 4.2.2 and earlier, and 5.0.x through 5.0.5. A remote authenticated 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

vBulletin: 5.0.0 - 5.0.5

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External links
https://packetstormsecurity.com/files/128691/vBulletin-5.x-4.x-Persistent-Cross-Site-Scripting.html
https://seclists.org/fulldisclosure/2014/Oct/55
https://seclists.org/fulldisclosure/2014/Oct/63
https://www.securityfocus.com/bid/70577
https://www.securitytracker.com/id/1031000
https://exchange.xforce.ibmcloud.com/vulnerabilities/97026
https://github.com/tintinweb/pub/tree/master/pocs/cve-2014-2021

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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. However, proof of concept for this vulnerability is available.