Project
Anti-Spam by CleanTalk
Date
Severity
Moderately Critical
Risk Score
13 ∕ 25 AC:Complex/A:None/CI:Some/II:Some/E:Theoretical/TD:Uncommon
Vulnerability
Cross Site Scripting
Affected versions
<7.x-6.2

Description

The Antispam by CleanTalk module provides a SpamFireWall (SFW) feature that blocks visitors whose IP appears on CleanTalk's blacklist and serves them a 403 challenge page.

The module builds that page by substituting the raw request URI and the blocked IP address into the page template, where the request URI is emitted inside a single-quoted HTML attribute; because neither value is escaped, a crafted request URI can break out of the attribute and run arbitrary script in the visitor's browser.

This vulnerability is mitigated by the fact that the SpamFireWall feature is not enabled by default and the targeted visitor's IP address must already be blocked by the firewall for the malicious page to be rendered.

Solution

Install the latest version.

If you use the Anti-Spam by CleanTalk module for Drupal 7, upgrade to cleantalk 7.x-6.2:

Reported by

Fixed by

Coordinated by