CVE-2017-18583

Post Pay Counter < 2.731 - PHP Object Injection

2017-09-16 00:00
Anonymous

Strategic Overview

Status
Patched in 2.731
Affected Plugin
Post Pay Counter
Affected Version
< 2.731
CVSS
9.8Critical
Weakness type
CWE-502 · Deserialization of Untrusted Data
CVE
CVE-2017-18583
View all Post Pay Counter vulnerabilities

At a glance

CVE-2017-18583 is a critical-severity Deserialization of Untrusted Data vulnerability in the Post Pay Counter WordPress plugin, affecting versions < 2.731. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 2.731; sites on affected versions should update now. Disclosed September 2017.

Vulnerability Overview

The Post Pay Counter plugin before 2.731 for WordPress has PHP Object Injection via deserialization of untrusted input via the 'import_settings_content' parameter.

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. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-502: Deserialization of Untrusted Data

Post Pay Counter < 2.731 carries this weakness at import_settings_content, and reaching it 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 Pay Counter the fix is 2.731: builds < 2.731 are affected, anything from 2.731 onward is not.

Remediation

Update to version 2.731, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Post Pay Counter: 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 Pay Counter 2.731 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Scanner
  • Alerts

External References

Related records

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