CVE-2022-4324

Custom Field Template <= 2.5.7 - Authenticated (Administrator+) PHP Object Injection

2022-12-09 00:00
thinhnguyen1337

Strategic Overview

Status
Patched in 2.5.8
Affected Plugin
Custom Field Template
Affected Version
<= 2.5.7
CVSS
7.2High
Weakness type
CWE-502 · Deserialization of Untrusted Data
CVE
CVE-2022-4324
View all Custom Field Template vulnerabilities

At a glance

CVE-2022-4324 is a high-severity Deserialization of Untrusted Data vulnerability in the Custom Field Template WordPress plugin, affecting versions <= 2.5.7. It carries a CVSS score of 7.2 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires an authenticated account at Administrator level or above. The issue is fixed in version 2.5.8; sites on affected versions should update now. Disclosed December 2022, reported by thinhnguyen1337.

Vulnerability Overview

The Custom Field Template plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 2.5.7 via deserialization of untrusted input in the custom_field_template_admin function. This allows administrator-level 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 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 Custom Field Template <= 2.5.7 takes an account at Administrator level or above. 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 Custom Field Template the fix is 2.5.8: builds <= 2.5.7 are affected, anything from 2.5.8 onward is not.

Remediation

Update to version 2.5.8, or a newer patched version

How does WordSec protect against this?

An attacker needs Administrator access first, so the firewall sees the attempt as traffic from a logged-in account: 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: Custom Field Template 2.5.8 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Scanner
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2022-4324https://www.wordfence.com/threat-intel/vulnerabilities/id/22a5020a-ab81-43be-b160-082347a2a2d9https://nvd.nist.gov/vuln/detail/CVE-2022-4324

Related records

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