SRC-2018-0033 : Vanilla Forums XenforoPassword splitHash unserialize Remote Code Execution Vulnerability

CVE ID:

CVE-2018-19500

CVSS Score:

6.6, (AV:N/AC:H/PR:H/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 required to exploit this vulnerability, however the authentication can be bypassed.

The specific flaw exists within the splitHash function of the XenforoPassword class. The issue results in an unserialize call via a crafted password value. 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/garden-password/commit/4f8b07907fcd3bcb90e5b0875e205dc65984c8b9

Disclosure Timeline:

• 2018-08-15 - Vulnerability reported to Vanilla
• 2018-08-17 - Vulnerability patched
• 2018-11-23 - Coordinated public release of advisory

Proof of Concept:

https://hackerone.com/reports/410212

Credit:

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