CVE-2025-5821

Case Theme User <= 1.0.3 - Authentication Bypass via Social Login

2025-08-22 18:31
Foxyyy

Strategic Overview

Status
Patched in 1.0.4
Affected Plugin
Case Theme User
Affected Version
<= 1.0.3
CVSS
9.8Critical
Weakness type
CWE-288 · Authentication Bypass Using an Alternate Path or Channel
CVE
CVE-2025-5821
View all Case Theme User vulnerabilities

At a glance

CVE-2025-5821 is a critical-severity Authentication Bypass Using an Alternate Path or Channel vulnerability in the Case Theme User WordPress plugin, affecting versions <= 1.0.3. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 1.0.4; sites on affected versions should update now. Disclosed August 2025, reported by Foxyyy.

Vulnerability Overview

The Case Theme User plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 1.0.3. This is due to the plugin not properly logging in a user with the data that was previously verified through the facebook_ajax_login_callback() function. This makes it possible for unauthenticated attackers to log in as administrative users, as long as they have an existing account on the site which can easily be created by default through the temp user functionality, and access to the administrative user's email.

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, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-288: Authentication Bypass Using an Alternate Path or Channel

Case Theme User <= 1.0.3 carries this weakness at facebook_ajax_login_callback(), and reaching it takes a caller who can reach the endpoint. Authentication bypass through an alternate path means the application has a second route to a protected action that skips the checks the primary route performs.

The protection on the main path becomes irrelevant, because the attacker simply uses the route that never asks. For Case Theme User the fix is 1.0.4: builds <= 1.0.3 are affected, anything from 1.0.4 onward is not.

Remediation

Update to version 1.0.4, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Case Theme User 1.0.4 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

Related records

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