Description
A critical vulnerability has been identified in the Instant Image Generator plugin of WordPress, specifically in the component responsible for handling image uploads. This vulnerability allows an attacker to upload malicious files to the web server.
Affected Product(s)
- Instant Image Generator (One Click Image Uploads from Pixabay, Pexels, and OpenAI) plugin versions from n/a through 1.5.4.
Technical Details
Instant Image Generator is a plugin developed by BdThemes for WordPress that enables users to upload images directly from popular online sources like Pixabay, Pexels, and OpenAI with a single click.
The vulnerability identified in this plugin is classified under CWE-434, which refers to ‘Unrestricted Upload of File with Dangerous Type.’ It arises from inadequate validation of uploaded files. The exploit mechanism relies on the pluginโs inability to properly restrict file types during the upload process.
An attacker can exploit this flaw to upload a malicious file, such as a web shell, enabling unauthorized execution of arbitrary commands on the server. This issue affects all versions of the plugin up to and including version 1.5.4. In technical terms, the vulnerability is due to the lack of a thorough file type check within the upload function. The plugin should ideally enforce strict MIME type checks and restrict file extensions to only those explicitly permitted. However, in its current state, it allows the uploading of any file type, some of which may possess harmful properties.
When a malicious file, such as a PHP shell, is uploaded, it can subsequently be executed by the attacker, leading to compromises of the web server and potentially expanding access to the broader network. The threat actors looking to exploit this vulnerability typically follow a pattern that starts with identifying an application running the vulnerable plugin version. Tools such as vulnerability scanners or manual inspection might be used to determine this information.
Post identification, the attacker crafts a malicious file designed to be uploaded using the plugin. This file could be a simple PHP script intended to execute commands on the server or a more sophisticated payload containing embedded malware capable of further actions like data exfiltration, privilege escalation, or lateral movement within the network.
This vulnerability poses a severe risk to web servers utilizing the Instant Image Generator plugin, as it provides an easy vector for unauthorized access, potentially leading to severe data breaches or alterations in the server configuration and data integrity. WordFence, Sucuri, or other WordPress security plugins might help in monitoring and blocking exploit attempts but cannot replace the need for an actual patch to fix the core issue.
The vulnerability CVE-2024-52377 has been cataloged in the NIST National Vulnerability Database (NVD), which provides additional technical details and suggests mitigation strategies. Further insights and patching information can be accessed through the Patchstack database (Patchstack).
Weakness
The weakness associated with this vulnerability is that the plugin does not restrict the types of files that can be uploaded. This unrestricted upload capability allows for potentially dangerous files, such as web shells, to be uploaded and executed on the web server.
Impact Assessment
If exploited, this vulnerability could allow an attacker to gain unauthorized access to sensitive data by uploading and executing arbitrary malicious scripts on the affected server. This can lead to a complete compromise of the web server, unauthorized access to the internal network, and exfiltration or destruction of data.
Active Exploitation
No known adversary groups exploiting this specific vulnerability have been documented so far, but the characteristics of the exploit suggest it could be a valuable attack vector for cybercriminals. Web server compromises are often precursors to more extensive attacks, including ransomware deployment and broader network infiltrations. Monitoring for signs of exploitation is crucial.
Ransomware Association
This vulnerability has the potential to be linked to ransomware attacks. Ransomware operators could leverage it to gain initial access to the system, deploy ransomware payloads, and then execute them to encrypt system files or exfiltrate sensitive data for extortion purposes.
Mitigation and Resolution
We have released a patch that addresses this vulnerability. Please update to version 1.5.5 or newer immediately to mitigate the risk. The updated version includes enhanced file type validations, ensuring that only safe file types can be uploaded through the plugin. It is imperative for users to install security patches and maintain their plugins up to date to protect against such vulnerabilities.
Recommendations
- We strongly recommend that all customers apply the latest patch as soon as possible.
- Ensure your plugins and WordPress installations are always updated to the latest versions.
- Employ additional security measures, such as web application firewalls (WAF), to monitor and block malicious traffic.
- Regularly inspect and audit uploaded files to identify and remove potentially harmful ones.
- Conduct periodic security assessments and vulnerability scans of your WordPress sites.
- Implement strict file upload policies and ensure all inputs are validated and sanitized.