WordPress Core < 6.0.3 - Cross-Site Request Forgery via wp-trackback.php

2022-10-18 00:00

Strategic Overview

Status: Patched in 3.7.40
Affected Core: WordPress 6.0
Affected Version: 3.6.1 – 6.0.2 · 25 branches
CVSS: 8.8High
Weakness type: CWE-352 · Cross-Site Request Forgery (CSRF)
CVE: CVE pending

At a glance

This record tracks a high-severity Cross-Site Request Forgery (CSRF) vulnerability in the WordPress 6.0 WordPress release line, affecting 3.6.1 – 6.0.2 · 25 branches. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 3.7.40; sites on affected versions should update now. Disclosed October 2022, reported by Simon Scannell.

Vulnerability Overview

WordPress Core is vulnerable to Cross-Site Request Forgery via wp-trackback.php in versions up to 6.0.3. This is due to the fact that the any request to wp-trackback.php would assume the identity of the user whose cookies are sent with the request. This would make it possible for an unauthenticated user to trigger a trackback assuming the identity of another user, granted they could trick that other user into performing the action. In new versions of WordPress, the identity will always be a non-existent user with the ID of 0, which represents an unauthenticated user.

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. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-352: Cross-Site Request Forgery (CSRF)

Reaching this weakness in WordPress 6.0 3.6.1 – 6.0.2 · 25 branches takes a caller who can reach the endpoint. Cross-site request forgery abuses the fact that browsers attach a victim's cookies to any request, so a state-changing action that only checks who you are, not whether you meant to act, can be triggered from another site.

An attacker who gets a logged-in user to load a crafted page can perform that action as them, with the impact scaling to whatever the victim's role is allowed to do. For WordPress 6.0 the fix is 3.7.40: builds 3.6.1 – 6.0.2 · 25 branches are affected, anything from 3.7.40 onward is not.

Remediation

Update to one of the following versions, or a newer patched version: 3.7.40, 3.8.40, 3.9.38, 4.0.37, 4.1.37, 4.2.34, 4.3.30, 4.4.29, 4.5.28, 4.6.25, 4.7.25, 4.8.21, 4.9.22, 5.0.18, 5.1.15, 5.2.17, 5.3.14, 5.4.12, 5.5.11, 5.6.10, 5.7.8, 5.8.6, 5.9.5, 6.0.3

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 3.7.40 is the step that ends it.

Firewall
Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/ddd06190-d0c1-445d-8c6f-4c7df3248db4

Related records

Same weakness class

Other vulnerabilities in WordPress 6.0

CVSS Vector

8.8

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

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