W3 Total Cache <= 0.9.7.3 - Improper Input Validation via openssl_verify

2019-05-07 00:00
Anonymous

Strategic Overview

Status
Patched in 0.9.7.4
Affected Plugin
W3 Total Cache
Affected Version
<= 0.9.7.3
CVSS
4.3Medium
Weakness type
CWE-20 · Improper Input Validation
CVE
CVE pending
View all W3 Total Cache vulnerabilities

At a glance

This record tracks a medium-severity Improper Input Validation vulnerability in the W3 Total Cache WordPress plugin, affecting versions <= 0.9.7.3. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 0.9.7.4; sites on affected versions should update now. Disclosed May 2019.

Vulnerability Overview

W3 Total Cache in versions 0.5 up to 0.9.7.3 does not sufficiently validate the "openssl_verify" result in "/services/MessageValidator/MessageValidator.php". A remote attacker can create a specially crafted certificate and bypass cryptographic checks.

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.

CWE-20: Improper Input Validation

W3 Total Cache <= 0.9.7.3 carries this weakness at openssl_verify, and reaching it 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 0.9.7.4: builds <= 0.9.7.3 are affected, anything from 0.9.7.4 onward is not.

Remediation

Update to version 0.9.7.4, 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 0.9.7.4 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/b002d1a1-a536-4865-b263-594390941ed4

Related records

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