WordPress Core < 6.0.2 - Stored Cross-Site Scripting via Plugin Deactivation and Deletion Errors

2022-08-30 00:00
Khalilov Moe

Strategic Overview

Status
Patched in 3.7.39
Affected Core
WordPress 6.0
Affected Version
3.6.1 – 6.0.1 · 25 branches
CVSS
4.4Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE pending
View all WordPress 6.0 vulnerabilities

At a glance

This record tracks a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the WordPress 6.0 WordPress release line, affecting 3.6.1 – 6.0.1 · 25 branches. It carries a CVSS score of 4.4 (reachable over the network). The issue is fixed in version 3.7.39; sites on affected versions should update now. Disclosed August 2022, reported by Khalilov Moe.

Vulnerability Overview

WordPress Core, in versions up to 6.0.2, is vulnerable to Stored Cross-Site Scripting that can be exploited when malicious content is injected into plugin code that triggers when an error occurs during plugin de-activation or during deletion. This requires an attacker have access to the modify the error message that is displayed either in the plugin's code or via a request parameter, in most cases it is likely to be the latter.

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 WordPress 6.0 3.6.1 – 6.0.1 · 25 branches 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 WordPress 6.0 the fix is 3.7.39: builds 3.6.1 – 6.0.1 · 25 branches are affected, anything from 3.7.39 onward is not.

Remediation

Update to one of the following versions, or a newer patched version: 3.7.39, 3.8.39, 3.9.37, 4.0.36, 4.1.36, 4.2.33, 4.3.29, 4.4.28, 4.5.27, 4.6.24, 4.7.24, 4.8.20, 4.9.21, 5.0.17, 5.1.14, 5.2.16, 5.3.13, 5.4.11, 5.5.10, 5.6.9, 5.7.7, 5.8.5, 5.9.4, 6.0.2

How does WordSec protect against this?

The attempt arrives as an ordinary request to WordPress 6.0: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: updating to 3.7.39 is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/300c6ea4-4eed-4be5-abfd-ec4ad9b741d3

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