#VU109837 Improper protection of alternate path in vBulletin - CVE-2025-48827

Vulnerability identifier: #VU109837

Vulnerability risk: Critical

CVSSv4.0: 9.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Red]

CVE-ID: CVE-2025-48827

CWE-ID: CWE-424

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
vBulletin
Web applications / Forum & blogging software

Vendor: vBulletin

Description

The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to missing authorization checks within protected API controllers methods. A remote non-authenticated attacker can send a specially crafted request to the website and execute arbitrary PHP code on the system.

Successful exploitation of the vulnerability requires PHP 8.1 to be used by the web application.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

vBulletin: 5.7.5 - 6.0.3

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External links
https://karmainsecurity.com/dont-call-that-protected-method-vbulletin-rce
https://forum.vbulletin.com/forum/vbulletin-announcements/vbulletin-announcements_aa/4491049-security-patch-released-for-vbulletin-6-x-and-5-7-5
https://github.com/advisories/GHSA-23fp-mrfv-cwv4

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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?

Yes. This vulnerability is being exploited in the wild.