A newly disclosed security flaw in the Motors WordPress theme could allow attackers with minimal access to escalate privileges and take full control of affected websites. The issue is an arbitrary file upload vulnerability that can be abused by logged-in users, including those with Subscriber privileges, to install and activate plugins. Since plugins can contain executable code, that capability can quickly turn into a complete site takeover.
Motors is widely used for automotive-focused websites like car dealership sites, rental platforms, and vehicle listing directories. Developed by StylemixThemes, it reportedly has 20,000+ active installations, which makes any serious vulnerability in the theme a high-value target for attackers who routinely scan for unpatched WordPress components.
The vulnerability impacts Motors versions 5.6.81 and below and has been assigned CVE-2025-64374. It was discovered and responsibly disclosed by Denver Jackson from the Patchstack Alliance community. Patchstack published an advisory highlighting how the flaw works and why it serves as a reminder of a common WordPress security pitfall: confusing request validation with permission control.
At the center of the issue is an AJAX handler tied to a backend function that can install plugins. The vulnerable flow includes a nonce, which is intended to help validate that a request came from a legitimate session and was not forged by a third party. The problem is that the code fails to perform a proper permission check before allowing the plugin installation and activation process to proceed.
This distinction matters. A nonce can help reduce the risk of CSRF-style attacks, but it is not meant to decide whether a user should be allowed to do something powerful. In this case, the nonce value can be accessed by Subscriber-level users in the WordPress admin area. That means any logged-in user who can retrieve the nonce can submit a request that supplies an arbitrary plugin URL.
If an attacker can point the installation process to a malicious plugin package, they can potentially upload and activate it. From there, the path to compromise is short. A malicious plugin can add rogue admin accounts, exfiltrate data, modify site content, inject malware, redirect traffic, or open persistent backdoors. In many real-world incidents, attackers do not need advanced exploits once they can run code through a plugin.
Patchstack also called out a broader lesson here that applies across many WordPress themes and plugins: nonces are not a substitute for authorization. WordPress developer guidance warns against relying on nonces for access control, and stresses that developers should protect sensitive actions with capability checks such as current_user_can().
The fix is straightforward and already available. The issue was patched in Motors version 5.6.82, which introduced a current_user_can permission check to ensure only authorized users can install and activate plugins. The patch was released on November 3, following disclosure to the vendor in September.
If you run Motors, the immediate step is to update to 5.6.82 or later. After updating, it is smart to review your environment for signs of abuse. Check the list of installed plugins for anything you do not recognize, review recent user account changes, and scan for unexpected administrator accounts. Look at WordPress audit logs if you have them, especially events related to plugin installs, activations, and file changes.
For added hardening, consider limiting who can register accounts, enforcing strong passwords and MFA, and using a security plugin or WAF to monitor suspicious admin activity. Even though this specific issue requires a logged-in account, attackers often obtain low-privilege credentials through reused passwords, phishing, or compromised third-party integrations.
For developers, the takeaway is clear: validate requests and enforce permissions as separate steps. Nonces can help confirm a request is intentional, but only capability checks should decide whether a user can perform high-impact actions like installing plugins.
