WP Super Cache <= 1.4.4 - PHP Object Injection

2015-09-25 00:00
Anonymous

Strategic Overview

Status
Patched in 1.4.5
Affected Plugin
WP Super Cache
Affected Version
< 1.4.5
CVSS
8.1High
Weakness type
CWE-502 · Deserialization of Untrusted Data
CVE
CVE pending
View all WP Super Cache vulnerabilities

At a glance

This record tracks a high-severity Deserialization of Untrusted Data vulnerability in the WP Super Cache WordPress plugin, affecting versions < 1.4.5. It carries a CVSS score of 8.1 (reachable over the network; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 1.4.5; sites on affected versions should update now. Disclosed September 2015.

Vulnerability Overview

The WP Super Cache plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 1.4.4 via deserialization of untrusted input. This allows attackers to inject a PHP Object into cache files. If the cache file is accessed, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-502: Deserialization of Untrusted Data

Reaching this weakness in WP Super Cache < 1.4.5 takes a caller who can reach the endpoint. Deserialization of untrusted data means the application reconstructs objects from input a caller controls, letting the attacker choose which classes get instantiated and what their properties hold.

A workable chain turns deserialization into file writes, deletions or code execution, depending on what the loaded classes do in their magic methods. For WP Super Cache the fix is 1.4.5: builds < 1.4.5 are affected, anything from 1.4.5 onward is not.

Remediation

Update to version 1.4.5, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to WP Super Cache: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: WP Super Cache 1.4.5 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Scanner
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/634ccd08-4f2e-4a06-8c64-dfe38fa3a481

Related records

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