CVE-2023-2023

Custom 404 Pro <= 3.7.2 - Reflected Cross-Site Scripting via 's'

2023-05-02 00:00
Chien Vuong

Strategic Overview

Status
Patched in 3.7.3
Affected Plugin
Custom 404 Pro
Affected Version
<= 3.7.2
CVSS
6.1Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2023-2023
View all Custom 404 Pro vulnerabilities

At a glance

CVE-2023-2023 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Custom 404 Pro WordPress plugin, affecting versions <= 3.7.2. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 3.7.3; sites on affected versions should update now. Disclosed May 2023, reported by Chien Vuong.

Vulnerability Overview

The Custom 404 Pro plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the ‘s’ parameter in versions up to, and including, 3.7.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

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.

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

Reaching this weakness in Custom 404 Pro <= 3.7.2 takes a caller who can reach the endpoint. 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 Custom 404 Pro the fix is 3.7.3: builds <= 3.7.2 are affected, anything from 3.7.3 onward is not.

Remediation

Update to version 3.7.3, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Custom 404 Pro: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Custom 404 Pro 3.7.3 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2023-2023https://www.wordfence.com/threat-intel/vulnerabilities/id/5e5bdc92-e682-4121-9ba5-167742f61138https://nvd.nist.gov/vuln/detail/CVE-2023-2023

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C