CVE-2025-39438

Theme Changer <= 1.4 - Cross-Site Request Forgery

2025-04-17 00:00

Strategic Overview

Status: Patched in 1.5
Affected Plugin: Theme Changer
Affected Version: <= 1.4
CVSS: 4.3Medium
Weakness type: CWE-352 · Cross-Site Request Forgery (CSRF)
CVE: CVE-2025-39438

At a glance

CVE-2025-39438 is a medium-severity Cross-Site Request Forgery (CSRF) vulnerability in the Theme Changer WordPress plugin, affecting versions <= 1.4. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 1.5; sites on affected versions should update now. Disclosed April 2025, reported by ch4r0n.

Vulnerability Overview

The Theme Changer plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 1.4. This is due to missing or incorrect nonce validation on the theme_changer_options() function. This makes it possible for unauthenticated attackers to update the 'theme_changer_password' option value granted they can trick a site administrator 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-352: Cross-Site Request Forgery (CSRF)

Theme Changer <= 1.4 carries this weakness at theme_changer_password, and reaching it 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 Theme Changer the fix is 1.5: builds <= 1.4 are affected, anything from 1.5 onward is not.

Remediation

Update to version 1.5, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Theme Changer: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Theme Changer 1.5 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2025-39438 https://www.wordfence.com/threat-intel/vulnerabilities/id/c7db2ec4-67cd-4ebb-8fbb-a1dc9def2f9a https://nvd.nist.gov/vuln/detail/CVE-2025-39438

CVSS Vector

4.3

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeUnchanged
ConfidentialityNone
IntegrityLow
AvailabilityNone

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