External risk intelligence

WordPress Background Image Cropper Remote Code Execution.

CVE advisorySeverity: CRITICAL (CVSS 9.3)

CVE-2024-58348

The vulnerability exists in a WordPress plugin, which is a web-based application component. By design, WordPress sites are typically deployed as public-facing web services. Since the vulnerable endpoint is accessible via the web server to handle background image cropping, it presents a commonly reachable attack surface for remote, unauthenticated interaction over the internet.

Unrestricted File Upload

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This vulnerability affects a WordPress plugin, allowing unauthenticated attackers to upload arbitrary files to a server. This could lead to the execution of malicious code, posing a significant risk to the integrity and operation of affected websites. The main concern is confirming relevance and exposure given the unauthenticated nature of the attack.

Unauthenticated file uploads can lead to code execution.
Potential for unauthorized server access and control.
Confirm relevance and exposure for affected systems.

Attack Path

How an attacker could exploit the issue

Attackers can initiate an attack by interacting with a specific file within the WordPress plugin, which is exposed through the web. This interaction allows them to upload malicious files to the server, leading to the execution of arbitrary code.

Attacker needs network access.
Vulnerable plugin endpoint triggers upload.
Remote code execution risk.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow unauthenticated attackers to upload arbitrary PHP files to a WordPress server by accessing a specific plugin endpoint, potentially leading to the execution of malicious code. This could impact the integrity and availability of the affected server.

Server-side code execution.
Upload arbitrary PHP files via `ups.php`.
Compromise of the web server.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in the WordPress Background Image Cropper plugin is likely to be a concern for teams managing WordPress sites, including platform, application, and security teams. The immediate first step is to determine the presence and accessibility of this plugin across your WordPress deployments. Confirming which sites use the plugin and whether the `ups.php` endpoint is exposed to the internet will help prioritize remediation efforts.

Platform and Security teams should own remediation.
Verify plugin presence and `ups.php` accessibility.
Plan for plugin removal or secure configuration.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the WordPress Background Image Cropper plugin?

This software is an extension for the WordPress content management system designed to help users modify and resize images used as backgrounds on their sites. It functions as a server-side component, processing image files directly on the web server infrastructure hosting the site to enable custom visual layouts.

How does CVE-2024-58348 work as a vulnerability?

This issue is classified under CWE-434, which refers to Unrestricted Upload of File with Dangerous Type. It occurs because the plugin fails to properly restrict the types of files that can be uploaded through its interface. Because the system does not validate incoming data, an attacker can upload a malicious script file instead of a legitimate image, allowing them to force the server to run unauthorized code.

What triggers this remote code execution bug?

The flaw is triggered by sending a specially crafted request to the 'ups.php' file located within the plugin directory. This action allows an attacker to bypass standard checks and save their own files to the server. Importantly, the vulnerability does not require any user interaction or authentication; however, the bug is only triggered if the 'ups.php' file is directly accessible to web traffic.

Do I need to worry about my exposure?

According to Halo Surface Signal, this vulnerability is highly relevant for WordPress sites because they are typically deployed as public-facing services. Since the 'ups.php' endpoint is designed to be reachable over the web, the plugin creates an entry point that is likely accessible to anyone on the internet, increasing the likelihood that an attacker could identify and target the vulnerable component.

What should I do if I use this plugin?

Your first step is to conduct an inventory to confirm whether this specific plugin is installed on any of your WordPress instances. If found, evaluate if the functionality is essential. Because the vulnerability allows for full server compromise, the most effective practical response is to disable and remove the plugin entirely from your environment until a secure version or official update is available.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.