CVE-2023-1196

Advanced Custom Fields <= 6.0.7 - Authenticated (Contributor+) PHP Object Injection

2023-04-03 00:00
Nguyen Huu Do

Strategic Overview

Status
Patched in 5.12.5
Affected Plugin
Advanced Custom Fields (ACF®)
Affected Version
5.12.4 – 6.0.7 · 2 branches
CVSS
8.8High
Weakness type
CWE-502 · Deserialization of Untrusted Data
CVE
CVE-2023-1196
View all Advanced Custom Fields (ACF®) vulnerabilities

At a glance

CVE-2023-1196 is a high-severity Deserialization of Untrusted Data vulnerability in the Advanced Custom Fields (ACF®) WordPress plugin, affecting versions 5.12.4 – 6.0.7 · 2 branches. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires an authenticated account at Contributor level or above. The issue is fixed in version 5.12.5; sites on affected versions should update now. Disclosed April 2023, reported by Nguyen Huu Do.

Vulnerability Overview

The Advanced Custom Fields plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 6.0.7 via deserialization of untrusted input in custom field values. This makes it possible for authenticated attackers, with contributor-level permissions, and above to inject a PHP Object. No POP chain appears to be 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 Advanced Custom Fields (ACF®) 5.12.4 – 6.0.7 · 2 branches takes an account at Contributor 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 Advanced Custom Fields (ACF®) the fix is 5.12.5: builds 5.12.4 – 6.0.7 · 2 branches are affected, anything from 5.12.5 onward is not.

Remediation

Update to one of the following versions, or a newer patched version: 5.12.5, 6.1.0

How does WordSec protect against this?

An attacker needs Contributor 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: Advanced Custom Fields (ACF®) 5.12.5 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Scanner
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2023-1196https://www.wordfence.com/threat-intel/vulnerabilities/id/b13e1916-2a02-4a91-acf1-6e5d7c55bd57https://nvd.nist.gov/vuln/detail/CVE-2023-1196

Related records

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