YITH WooCommerce Compare <= 2.0.9 - Unauthenticated PHP Object Injection

2016-11-08 00:00
Yorick Koster,

Strategic Overview

Status
Patched in 2.1.0
Affected Plugin
YITH WooCommerce Compare
Affected Version
<= 2.0.9
CVSS
8.8High
Weakness type
CWE-502 · Deserialization of Untrusted Data
CVE
CVE pending
View all YITH WooCommerce Compare vulnerabilities

At a glance

This record tracks a high-severity Deserialization of Untrusted Data vulnerability in the YITH WooCommerce Compare WordPress plugin, affecting versions <= 2.0.9. 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 2.1.0; sites on affected versions should update now. Disclosed November 2016, reported by Yorick Koster,.

Vulnerability Overview

The YITH WooCommerce Compare plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 2.0.9 via deserialization of untrusted input from the 'yith_woocompare_list' cookie. This allows unauthenticated attackers to inject a PHP Object. It has been confirmed that this vulnerability allows attackers to execute arbitrary PHP code.

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 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

YITH WooCommerce Compare <= 2.0.9 carries this weakness at yith_woocompare_list, and reaching it takes no account at all. 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 YITH WooCommerce Compare the fix is 2.1.0: builds <= 2.0.9 are affected, anything from 2.1.0 onward is not.

Remediation

Update to version 2.1.0, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: 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: YITH WooCommerce Compare 2.1.0 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Scanner
  • Login Security

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/fe02377a-8d09-4d86-a049-3002516cf933

Related records

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