W3 Total Cache <= 0.9.4.1 - Weak validation of Amazon SNS push messages

2016-11-10 00:00
Anonymous

Strategic Overview

Status
Patched in 0.9.5
Affected Plugin
W3 Total Cache
Affected Version
<= 0.9.4.1
CVSS
7.2High
Weakness type
CWE-20 · Improper Input Validation
CVE
CVE pending
View all W3 Total Cache vulnerabilities

At a glance

This record tracks a high-severity Improper Input Validation vulnerability in the W3 Total Cache WordPress plugin, affecting versions <= 0.9.4.1. It carries a CVSS score of 7.2 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 0.9.5; sites on affected versions should update now. Disclosed November 2016.

Vulnerability Overview

The W3 Total Cache plugin for WordPress is vulnerable to weak validation of Amazon SNS push messages in versions up to, and including, 0.9.4.1. This makes it possible for attackers to perform a variety of actions concerning the server's cache, such as performing a Denial of Service attack on the site.

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, and no interaction from a victim user.

CWE-20: Improper Input Validation

Reaching this weakness in W3 Total Cache <= 0.9.4.1 takes a caller who can reach the endpoint. Improper input validation means the application accepts input without confirming it has the form, type or range the code downstream assumes.

The concrete impact depends on where the unvalidated value lands, which is why records in this class range from cosmetic bugs to full compromise. For W3 Total Cache the fix is 0.9.5: builds <= 0.9.4.1 are affected, anything from 0.9.5 onward is not.

Remediation

Update to version 0.9.5, 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 0.9.5 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/9373c82d-15a8-495a-8290-1b85c096f7e5

Related records

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