Overview
A critical vulnerability has been discovered in the PostGallery plugin for WordPress, identified as CVE-2025-13543. This vulnerability allows authenticated attackers with subscriber-level permissions or higher to upload arbitrary files to the affected site’s server. This can lead to remote code execution (RCE) and complete compromise of the WordPress website.
This vulnerability exists in all versions of the PostGallery plugin up to and including version 1.12.5.
Technical Details
The vulnerability resides in the PostGalleryUploader class functions within the PostGallery plugin. Specifically, the file type validation is insufficient, allowing attackers to bypass security checks and upload malicious files, such as PHP scripts, disguised as other file types. This insufficient validation allows unauthorized users to place executable files within the web server’s document root.
CVSS Analysis
- CVE ID: CVE-2025-13543
- Severity: HIGH
- CVSS Score: 8.8
A CVSS score of 8.8 indicates a high-severity vulnerability. This score reflects the ease of exploitation and the potential impact of a successful attack.
Possible Impact
Successful exploitation of this vulnerability can have severe consequences, including:
- Remote Code Execution (RCE): Attackers can execute arbitrary code on the server, potentially gaining full control of the website.
- Website Defacement: Attackers can modify the website’s content, damaging its reputation.
- Data Theft: Attackers can steal sensitive data, including user credentials, database information, and financial records.
- Malware Distribution: Attackers can use the compromised website to distribute malware to visitors.
- Backdoor Installation: Attackers can install a backdoor to maintain persistent access to the compromised server, even after the initial vulnerability is patched.
Mitigation and Patch Steps
- Immediately Update the Plugin: Upgrade the PostGallery plugin to the latest version as soon as a patched version is available. Check the WordPress plugin repository or the plugin developer’s website for updates.
- Disable the Plugin: If an update is not immediately available, disable the PostGallery plugin until a patched version can be installed. This will temporarily prevent exploitation of the vulnerability.
- Web Application Firewall (WAF): Implement a Web Application Firewall (WAF) to filter malicious traffic and block attempts to exploit the vulnerability. Configure the WAF with rules to prevent arbitrary file uploads.
- Review User Permissions: Carefully review user roles and permissions on your WordPress site. Limit the number of users with upload capabilities and ensure that only trusted users have administrative privileges.
- Monitor Website Activity: Closely monitor your website’s logs for suspicious activity, such as unusual file uploads or unauthorized access attempts.
References
PostGalleryUploader.php Source Code
Wordfence Threat Intelligence Report
