CVE-2024-39631 Overview
CVE-2024-39631 is a Cross-Site Scripting (XSS) vulnerability in the Contest Gallery WordPress plugin developed by Wasiliy Strecker. The flaw affects all plugin versions up to and including 23.1.2. The vulnerability stems from improper neutralization of user-supplied input during web page generation, classified as [CWE-79]. Attackers can inject malicious scripts that execute in the browser context of victims who interact with a crafted link or page element. Successful exploitation can lead to session data theft, unauthorized actions performed on behalf of the victim, and defacement of rendered content within the WordPress site.
Critical Impact
Reflected or stored script injection in a WordPress plugin used for gallery contests, enabling attackers to compromise user sessions and pivot within the site's rendered scope.
Affected Products
- Contest Gallery plugin for WordPress, all versions through 23.1.2
- Vendor: Wasiliy Strecker / ContestGallery (contest-gallery)
- CPE: cpe:2.3:a:contest-gallery:contest_gallery:*:*:*:*:*:wordpress:*:*
Discovery Timeline
- 2024-08-01 - CVE-2024-39631 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-39631
Vulnerability Analysis
The vulnerability exists in the Contest Gallery plugin's handling of user-controlled input rendered back to the browser. The plugin fails to properly sanitize or encode input before including it in HTML output. This allows attackers to inject arbitrary JavaScript that executes in the browser of any user who views the affected page or clicks a crafted link.
The attack changes the security scope, meaning injected script can affect resources beyond the vulnerable component itself. User interaction is required, typically in the form of clicking a malicious link or loading attacker-influenced content. The impact covers both confidentiality and integrity of user session data within the affected WordPress site.
Root Cause
The root cause is missing or insufficient output encoding on parameters processed by the Contest Gallery plugin before rendering to the DOM. Input passing through vulnerable request parameters or stored fields reaches HTML sinks without being escaped for the appropriate context, allowing attacker-controlled markup and script tags to execute.
Attack Vector
An attacker crafts a URL or submits content containing JavaScript payloads targeting a vulnerable Contest Gallery endpoint. When a WordPress user, including administrators, loads the resulting page, the injected script executes with the privileges of that user's browser session. Attackers can steal cookies, perform authenticated actions through the WordPress admin interface, or redirect users to attacker-controlled infrastructure.
Refer to the Patchstack Vulnerability Report for additional technical context.
Detection Methods for CVE-2024-39631
Indicators of Compromise
- Unexpected <script> tags, event handlers such as onerror or onload, or javascript: URIs appearing in Contest Gallery request parameters or stored records.
- WordPress access logs showing requests to Contest Gallery endpoints containing URL-encoded HTML or script fragments.
- New or modified administrator accounts, plugin configurations, or posts following user visits to Contest Gallery pages.
Detection Strategies
- Inspect web server and WordPress logs for query strings targeting Contest Gallery endpoints that include suspicious characters like <, >, or %3C.
- Deploy a Web Application Firewall (WAF) rule set that flags XSS payload patterns directed at /wp-content/plugins/contest-gallery/ paths.
- Enable Content Security Policy (CSP) violation reporting to surface inline script execution attempts on pages rendered by the plugin.
Monitoring Recommendations
- Monitor for outbound requests from browsers to unknown domains immediately after users visit Contest Gallery pages.
- Alert on WordPress administrator session activity originating from unusual IP addresses or user agents.
- Track plugin version inventory across managed WordPress sites and flag any instance running 23.1.2 or earlier.
How to Mitigate CVE-2024-39631
Immediate Actions Required
- Upgrade the Contest Gallery plugin to the latest version released after 23.1.2 that addresses the XSS flaw.
- If an upgrade is not immediately possible, deactivate the Contest Gallery plugin until a patched version is deployed.
- Force password resets and session invalidation for any WordPress administrator who may have interacted with a suspicious Contest Gallery link.
Patch Information
Consult the Patchstack Vulnerability Report for patch availability and vendor remediation guidance. Apply the fixed release from the WordPress plugin repository as soon as it becomes available.
Workarounds
- Restrict access to the WordPress administrative interface using IP allowlisting or reverse proxy authentication.
- Deploy a WAF signature that blocks XSS payloads targeting Contest Gallery request parameters.
- Enforce a strict Content Security Policy that disallows inline scripts and untrusted script sources on pages rendered by the plugin.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
