Simple Ads Manager <= 2.9.8.125 - Unauthenticated PHP Objection Injection

2017-03-17 00:00
Yorick Koster,

Strategic Overview

Status
Patched in 2.10.0.130
Affected Plugin
Simple Ads Manager
Affected Version
< 2.10.0.130
CVSS
8.3High
Weakness type
CWE-502 · Deserialization of Untrusted Data
CVE
CVE pending
View all Simple Ads Manager vulnerabilities

At a glance

This record tracks a high-severity Deserialization of Untrusted Data vulnerability in the Simple Ads Manager WordPress plugin, affecting versions < 2.10.0.130. It carries a CVSS score of 8.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 2.10.0.130; sites on affected versions should update now. Disclosed March 2017, reported by Yorick Koster,.

Vulnerability Overview

The Simple Ads Manager plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 2.9.8.125 via deserialization of untrusted input in the vulnerable function 'unserialize'. This allows unauthenticated attackers to inject a PHP Object. No POP chain is present in the vulnerable plugin. If a POP chain is present via an additional plugin or theme installed on the target system, 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, 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-502: Deserialization of Untrusted Data

Simple Ads Manager < 2.10.0.130 carries this weakness at unserialize, 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 Simple Ads Manager the fix is 2.10.0.130: builds < 2.10.0.130 are affected, anything from 2.10.0.130 onward is not.

Remediation

Update to version 2.10.0.130, 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: Simple Ads Manager 2.10.0.130 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/02665811-15ba-434c-a4d0-df5402a128f4

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C