SRC-2018-0032 : Vanilla Forums Gdn_Format unserialize Unserialize Remote Code Execution Vulnerability

Vulnerability Details:

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Vanilla Forums. Authentication is required to exploit this vulnerability, however the authentication can be bypassed.

The specific flaw exists within the unserialize function of the Gdn_Format class. The issue results in an unserialize via a crafted phar archive. An attacker can leverage this vulnerability to execute code under the context of the web server.

Affected Vendors:

Vanilla

Affected Products:

Vanilla Forums

Vendor Response:

Vanilla has issued an update to correct these vulnerabilities. More details can be found at:
<https://github.com/vanilla/vanilla/commit/e8b4c23d9b68c8cc904e76d9e012538e426e8303&gt;
Proof of Concept:
<https://hackerone.com/reports/407552&gt;