WordPress Core < 6.2.1 - Insufficient Sanitization of Block Attributes

2023-05-16 00:00
Anonymous

Strategic Overview

Status
Patched in 4.1.38
Affected Core
WordPress 6.2
Affected Version
4.1 – < 6.2.1 · 23 branches
CVSS
6.4Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE pending
View all WordPress 6.2 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 6.2 WordPress release line, affecting 4.1 – < 6.2.1 · 23 branches. It carries a CVSS score of 6.4 (reachable over the network; low attack complexity). The issue is fixed in version 4.1.38; sites on affected versions should update now. Disclosed May 2023.

Vulnerability Overview

WordPress Core failed to sufficiently sanitize block attributes in versions up to, and including, 6.2. This makes it possible for authenticated attackers with contributor-level and above permissions to embed arbitrary content in HTML comments on the page, though Cross-Site Scripting may be possible when combined with an additional vulnerability.

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.

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

Reaching this weakness in WordPress 6.2 4.1 – < 6.2.1 · 23 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 6.2 the fix is 4.1.38: builds 4.1 – < 6.2.1 · 23 branches are affected, anything from 4.1.38 onward is not.

Remediation

Update to one of the following versions, or a newer patched version: 4.1.38, 4.2.35, 4.3.31, 4.4.30, 4.5.29, 4.6.26, 4.7.26, 4.8.22, 4.9.23, 5.0.19, 5.1.16, 5.2.18, 5.3.15, 5.4.13, 5.5.12, 5.6.11, 5.7.9, 5.8.7, 5.9.6, 6.0.4, 6.1.2, 6.2.1

How does WordSec protect against this?

The attempt arrives as an ordinary request to WordPress 6.2: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: updating to 4.1.38 is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/834c92ba-8b48-4ae3-9073-085e8f559762

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