CVE-2016-10948

Post Indexer <= 3.0.6.1 - PHP Object Injection

2016-11-17 00:00
Glyn Wintle

Strategic Overview

Status
Patched in 3.0.6.2
Affected Plugin
Post Indexer
Affected Version
< 3.0.6.2
CVSS
8.1High
Weakness type
CWE-502 · Deserialization of Untrusted Data
CVE
CVE-2016-10948
View all Post Indexer vulnerabilities

At a glance

CVE-2016-10948 is a high-severity Deserialization of Untrusted Data vulnerability in the Post Indexer WordPress plugin, affecting versions < 3.0.6.2. 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 3.0.6.2; sites on affected versions should update now. Disclosed November 2016, reported by Glyn Wintle.

Vulnerability Overview

The Post Indexer plugin before 3.0.6.2 for WordPress has incorrect handling of data passed to the unserialize function.

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 Post Indexer < 3.0.6.2 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 Post Indexer the fix is 3.0.6.2: builds < 3.0.6.2 are affected, anything from 3.0.6.2 onward is not.

Remediation

Update to version 3.0.6.2, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Post Indexer: 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: Post Indexer 3.0.6.2 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Scanner
  • Alerts

External References

Related records

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