CVE-2024-51759: SVT Simple Plugin XSS Vulnerability

CVE-2024-51759 Overview

CVE-2024-51759 is a reflected Cross-Site Scripting (XSS) vulnerability [CWE-79] in the Detlef Beyer SVT Simple WordPress plugin. The flaw affects all versions of svt-simple up to and including 1.0.1. The plugin fails to properly neutralize user-supplied input during web page generation, allowing attackers to inject arbitrary JavaScript that executes in a victim's browser.

Exploitation requires user interaction, typically by luring an authenticated or unauthenticated user to click a crafted link. Successful exploitation can lead to session theft, credential harvesting, or actions performed under the victim's privileges on the affected WordPress site.

Critical Impact
Attackers can execute arbitrary JavaScript in the browser of any user who visits a crafted URL, enabling session hijacking, defacement, and privilege abuse against WordPress administrators.

Affected Products

Detlef Beyer SVT Simple WordPress plugin (svt-simple)
All versions from n/a through 1.0.1
WordPress installations running the vulnerable plugin

Discovery Timeline

2024-11-09 - CVE-2024-51759 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-51759

Vulnerability Analysis

The vulnerability stems from improper neutralization of input during web page generation within the SVT Simple plugin. User-controlled parameters are reflected back into the HTTP response without adequate output encoding or input sanitization. When a browser renders the response, injected script content executes in the context of the affected WordPress origin.

Reflected XSS vulnerabilities of this class are commonly triggered through query string parameters embedded in phishing links. The scope change indicated in the CVSS vector reflects that injected script can impact resources beyond the vulnerable component, including cookies, DOM content, and API calls tied to the WordPress domain.

Attackers targeting WordPress administrators can leverage this flaw to pivot toward privileged actions such as creating rogue accounts, modifying plugin configuration, or injecting persistent backdoors through the admin dashboard.

Root Cause

The root cause is missing or inadequate output encoding of user-supplied data before it is embedded into HTML responses generated by the plugin. The plugin does not apply WordPress sanitization primitives such as esc_html(), esc_attr(), or wp_kses() to reflected parameters, allowing raw markup and script tags to reach the browser.

Attack Vector

The attack vector is network-based and requires user interaction. An attacker crafts a URL containing a malicious payload in a vulnerable parameter and delivers it through phishing, social engineering, or a malicious referrer. When the target visits the URL on a site running the affected plugin, the payload is reflected into the response and executed by the browser. Full technical details are available in the Patchstack Vulnerability Report.

No verified public proof-of-concept code has been released. The vulnerability mechanism follows standard reflected XSS patterns documented under [CWE-79].

Detection Methods for CVE-2024-51759

Indicators of Compromise

Web server access logs containing query strings with <script>, javascript:, onerror=, or URL-encoded equivalents (%3Cscript%3E) targeting SVT Simple plugin endpoints
Unexpected outbound requests from administrator browsers to attacker-controlled domains following visits to plugin URLs
New or modified WordPress administrator accounts created shortly after suspicious link clicks

Detection Strategies

Deploy Web Application Firewall (WAF) rules that inspect requests to /wp-content/plugins/svt-simple/ paths for reflected XSS patterns
Monitor WordPress audit logs for anomalous administrative activity correlated with suspicious HTTP referrers
Enable Content Security Policy (CSP) reporting to capture inline script violations that indicate injection attempts

Monitoring Recommendations

Alert on HTTP requests containing HTML control characters or script tags in query parameters targeting the plugin
Track browser console errors and CSP violation reports centrally to identify exploitation attempts
Review plugin inventory regularly and flag installations of svt-simple version 1.0.1 or earlier

How to Mitigate CVE-2024-51759

Immediate Actions Required

Identify all WordPress instances running the SVT Simple plugin and inventory the installed version
Deactivate and remove the svt-simple plugin if no vendor patch is available for your installed version
Rotate WordPress administrator credentials and invalidate active sessions if exploitation is suspected
Deploy WAF signatures blocking reflected XSS payloads against plugin endpoints

Patch Information

At the time of publication, no fixed version has been identified in the referenced advisory. The vulnerability affects SVT Simple through 1.0.1. Consult the Patchstack Vulnerability Report for the latest remediation status.

Workarounds

Remove the plugin until the vendor releases a patched version that properly sanitizes user input
Enforce a strict Content Security Policy that disallows inline scripts and untrusted script sources
Restrict access to the WordPress administration interface through IP allowlisting or VPN
Train administrators to avoid clicking untrusted links to WordPress sites they manage

bash

# Example restrictive Content Security Policy header for WordPress (nginx)
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self'" always;