CVE-2024-49276: Clio Grow Form XSS Vulnerability

CVE-2024-49276 Overview

CVE-2024-49276 is a reflected Cross-Site Scripting (XSS) vulnerability [CWE-79] in the Clio Grow WordPress plugin (clio-grow-form) developed by cliogrow. The flaw affects all versions up to and including 1.0.2. Attackers can inject malicious scripts that execute in the context of a victim's browser when the victim clicks a crafted link.

The vulnerability stems from improper neutralization of user input during web page generation. Successful exploitation requires user interaction and can lead to session theft, credential harvesting, or unauthorized actions in the WordPress site context.

Critical Impact

Reflected XSS enables attackers to execute arbitrary JavaScript in victim browsers, potentially compromising administrator sessions and enabling account takeover on affected WordPress sites.

Affected Products

• Clio Grow WordPress plugin (clio-grow-form)
• All versions from initial release through 1.0.2
• WordPress installations using the cliogrow integration plugin

Discovery Timeline

• 2024-10-17 - CVE-2024-49276 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2024-49276

Vulnerability Analysis

The Clio Grow plugin fails to properly sanitize and encode user-supplied input before reflecting it back in HTTP responses. When a request parameter contains JavaScript payloads, the plugin renders the unsanitized content directly into the generated HTML page.

The vulnerability is classified under [CWE-79] (Improper Neutralization of Input During Web Page Generation). The EPSS score is 0.312% at the 54.6 percentile, indicating moderate exploitation likelihood. No public exploit code is currently catalogued, and the issue is not listed in the CISA Known Exploited Vulnerabilities catalog.

The scope change indicator means a successful attack impacts resources beyond the vulnerable component, typically reflecting that injected scripts execute in the security context of the WordPress site rather than the plugin itself.

Root Cause

The root cause is missing output encoding on reflected request parameters. The plugin accepts input from URL query strings or form fields and embeds the values into HTML responses without applying contextual escaping functions such as esc_html(), esc_attr(), or wp_kses().

Attack Vector

An attacker crafts a URL containing a malicious JavaScript payload as a parameter value. The attacker delivers this URL to a victim through phishing emails, social media, or compromised websites. When the victim clicks the link while authenticated to the affected WordPress site, the injected script executes in their browser session.

The attacker can then exfiltrate session cookies, perform actions on behalf of the victim, redirect to attacker-controlled pages, or deliver follow-on payloads. Administrator-level victims expose the entire WordPress instance to compromise.

No verified proof-of-concept code is available. See the PatchStack WordPress Vulnerability Report for additional technical context.

Detection Methods for CVE-2024-49276

Indicators of Compromise

• HTTP requests to Clio Grow plugin endpoints containing URL-encoded <script> tags, javascript: URIs, or event handlers such as onerror= and onload=
• Outbound requests from user browsers to unfamiliar domains shortly after visiting WordPress pages hosting the plugin
• Unexpected administrator session activity originating from unusual IP addresses or user agents
• Web server access logs showing referrers from external phishing or redirector domains

Detection Strategies

• Inspect web server and WAF logs for query strings containing common XSS payload patterns targeting clio-grow-form parameters
• Deploy content security policy (CSP) reporting to surface inline script execution attempts on plugin pages
• Correlate browser telemetry with WordPress audit logs to identify script execution tied to suspicious referrers

Monitoring Recommendations

• Enable WordPress audit logging for administrator account actions and configuration changes
• Monitor authentication events for impossible-travel patterns following user clicks on external links
• Alert on creation of new administrator users, plugin installations, or theme modifications outside maintenance windows

How to Mitigate CVE-2024-49276

Immediate Actions Required

• Identify all WordPress installations running the clio-grow-form plugin version 1.0.2 or earlier
• Deactivate the Clio Grow plugin until a patched version is verified and deployed
• Force password resets for WordPress administrator accounts that may have been exposed
• Review recent administrative activity for unauthorized changes

Patch Information

At the time of NVD publication, no fixed version is listed in the advisory. Monitor the PatchStack WordPress Vulnerability Report and the official plugin repository for an updated release addressing the reflected XSS issue.

Workarounds

• Deploy a web application firewall (WAF) rule blocking requests containing XSS payload signatures targeting plugin endpoints
• Apply a strict Content-Security-Policy header disallowing inline scripts on pages where the plugin renders
• Restrict access to the plugin's form endpoints by IP allowlist or authentication where feasible
• Train administrators to avoid clicking unsolicited links referencing the WordPress site

# Example nginx configuration to block common XSS patterns on plugin endpoints
location ~* /wp-content/plugins/clio-grow-form/ {
    if ($args ~* "(<|%3C)script|javascript:|onerror=|onload=") {
        return 403;
    }
    add_header Content-Security-Policy "default-src 'self'; script-src 'self'";
}