SRC-2018-0030 : Vanilla Forums domGetImages getimagesize Unserialize Remote Code Execution Vulnerability

CVE ID:

CVE-2018-18903

CVSS Score:

8.1, (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)

Affected Vendors:

Vanilla

Affected Products:

Vanilla Forums

Vulnerability Details:

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Vanilla Forums. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the domGetImages function of the ImportController 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.

Vendor Response:

Vanilla has issued an update to correct these vulnerabilities. More details can be found at:
https://github.com/vanilla/vanilla/commit/7e931112fb31da12e1566f6aa82c3f57cd3e8bcc

Disclosure Timeline:

• 2018-08-17 - Vulnerability reported to Vanilla
• 2018-08-23 - Vulnerability patched
• 2018-10-02 - Uncoordinated public release of advisory

Credit:

This vulnerability was discovered by Steven Seeley (mr_me) of Source Incite