CVE-2024-49593

Advanced Custom Fields <= 6.3.8 & Secure Custom Fields <= 6.3.6.2 - Authenticated (Admin+) Stored Cross-Site Scripting

2024-10-15 00:00
Duc Luong Tran

Strategic Overview

Status
Patched in 6.3.9
Affected Plugin
Advanced Custom Fields Pro
Affected Version
<= 6.3.8
CVSS
4.4Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2024-49593
View all Advanced Custom Fields Pro vulnerabilities

At a glance

CVE-2024-49593 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Advanced Custom Fields Pro WordPress plugin, affecting versions <= 6.3.8. It carries a CVSS score of 4.4 (reachable over the network). Exploitation requires an authenticated account at Admin level or above. The issue is fixed in version 6.3.9; sites on affected versions should update now. Disclosed October 2024, reported by Duc Luong Tran.

Vulnerability Overview

The Advanced Custom Fields & Secure Custom Fields plugins for WordPress are vulnerable to Stored Cross-Site Scripting via ACF field labels in all versions up to, and including, 6.3.8 & 6.3.6.2 respectively due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level access, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled. Please follow the reference listed in this vulnerability record for instructions on how to update to the latest version of ACF that patches this issue and ensures accessibility to updates moving forward. Special note: only the minified files in Secure Custom Fields have been patched meaning the source build files are still vulnerable.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, and no interaction from a victim user.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Reaching this weakness in Advanced Custom Fields Pro <= 6.3.8 takes an account at Admin level or above. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Advanced Custom Fields Pro the fix is 6.3.9: builds <= 6.3.8 are affected, anything from 6.3.9 onward is not.

Remediation

Update to version 6.3.9, or a newer patched version

How does WordSec protect against this?

An attacker needs Admin 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. None of that substitutes for the fix: Advanced Custom Fields Pro 6.3.9 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2024-49593https://www.wordfence.com/threat-intel/vulnerabilities/id/b3552de0-3e0b-4529-a757-a31c69a06122https://nvd.nist.gov/vuln/detail/CVE-2024-49593

Related records

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