W3 Total Cache <= 0.9.4 - Cross-Site Request Forgery leading to Stored Cross-Site Scripting

2014-09-08 00:00
Voxel@Night

Strategic Overview

Status
Patched in 0.9.4.1
Affected Plugin
W3 Total Cache
Affected Version
<= 0.9.4
CVSS
8.8High
Weakness type
CWE-352 · Cross-Site Request Forgery (CSRF)
CVE
CVE pending
View all W3 Total Cache vulnerabilities

At a glance

This record tracks a high-severity Cross-Site Request Forgery (CSRF) vulnerability in the W3 Total Cache WordPress plugin, affecting versions <= 0.9.4. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 0.9.4.1; sites on affected versions should update now. Disclosed September 2014, reported by Voxel@Night.

Vulnerability Overview

The W3 Total Cache plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 0.9.4. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page via forged request granted they can trick a site administrator into performing an action such as clicking on a link.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-352: Cross-Site Request Forgery (CSRF)

Reaching this weakness in W3 Total Cache <= 0.9.4 takes a caller who can reach the endpoint. Cross-site request forgery abuses the fact that browsers attach a victim's cookies to any request, so a state-changing action that only checks who you are, not whether you meant to act, can be triggered from another site.

An attacker who gets a logged-in user to load a crafted page can perform that action as them, with the impact scaling to whatever the victim's role is allowed to do. For W3 Total Cache the fix is 0.9.4.1: builds <= 0.9.4 are affected, anything from 0.9.4.1 onward is not.

Remediation

Update to version 0.9.4.1, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to W3 Total Cache: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: W3 Total Cache 0.9.4.1 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/84227fd2-c322-45e3-82cd-70e1d870eceb

Related records

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