CVE-2019-25445: Fiverr Clone Script XSS Vulnerability

CVE-2019-25445 Overview

CVE-2019-25445 is a reflected Cross-Site Scripting (XSS) vulnerability affecting Fiverr Clone Script version 1.2.2 by phpscriptsmall. This vulnerability allows unauthenticated attackers to inject malicious scripts by manipulating the keyword parameter in the search-results.php file. When a victim clicks on a crafted URL containing script tags in the keyword parameter, arbitrary JavaScript executes within their browser context.

Critical Impact

Unauthenticated attackers can execute arbitrary JavaScript in victims' browsers, potentially stealing session cookies, credentials, or performing actions on behalf of authenticated users.

Affected Products

• phpscriptsmall Fiverr Clone Script version 1.2.2

Discovery Timeline

• 2026-02-20 - CVE CVE-2019-25445 published to NVD
• 2026-02-26 - Last updated in NVD database

Technical Details for CVE-2019-25445

Vulnerability Analysis

This vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation), commonly known as Cross-Site Scripting (XSS). The Fiverr Clone Script fails to properly sanitize user-supplied input in the keyword parameter before reflecting it back in the search results page. This allows attackers to craft malicious URLs that, when visited by unsuspecting users, execute attacker-controlled JavaScript code within the security context of the vulnerable application.

The vulnerability requires user interaction—specifically, a victim must click on a malicious link containing the XSS payload. Once triggered, the attacker can perform various malicious actions including session hijacking, credential theft, defacement, and phishing attacks targeting the application's users.

Root Cause

The root cause of this vulnerability is insufficient input validation and output encoding in the search-results.php script. The application directly reflects user input from the keyword GET parameter into the HTML response without proper sanitization or encoding. This allows HTML and JavaScript content to be injected and rendered as executable code rather than being treated as plain text.

Attack Vector

The attack is network-based and requires no authentication. An attacker crafts a malicious URL targeting search-results.php with a payload in the keyword parameter containing script tags or other XSS vectors. The attacker then distributes this URL through social engineering methods such as phishing emails, forum posts, or compromised websites. When a victim clicks the link, the malicious script executes in their browser with full access to the application's DOM, cookies, and session data.

The vulnerability can be exploited by embedding script tags within the keyword parameter of the search functionality. When the search results page renders, the unsanitized input is reflected directly into the HTML response, causing the browser to execute the injected JavaScript code. For detailed technical analysis, see the Exploit-DB #46637 and the VulnCheck Advisory on Fiverr Clone.

Detection Methods for CVE-2019-25445

Indicators of Compromise

• Suspicious URL patterns containing script tags or encoded JavaScript in the keyword parameter
• Web server logs showing requests to search-results.php with unusual or encoded payloads
• Reports of users experiencing unexpected browser behavior or pop-ups when using the search functionality

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block common XSS patterns in GET parameters
• Monitor web server access logs for requests containing <script>, javascript:, onerror=, or other XSS indicators in URL parameters
• Deploy browser-based Content Security Policy (CSP) headers to restrict inline script execution

Monitoring Recommendations

• Enable detailed logging for all requests to search-results.php and analyze for anomalous patterns
• Set up alerts for requests containing HTML-encoded characters or script tags in query strings
• Implement real-time security monitoring to detect and respond to XSS exploitation attempts

How to Mitigate CVE-2019-25445

Immediate Actions Required

• Upgrade Fiverr Clone Script to a patched version if available from phpscriptsmall
• Implement input validation to reject or sanitize any special characters in the keyword parameter
• Apply output encoding (HTML entity encoding) to all user-supplied data before rendering in HTML responses

Patch Information

No official vendor patch information is available in the CVE data. Organizations using Fiverr Clone Script version 1.2.2 should contact phpscriptsmall directly for security updates or consider implementing manual mitigations. For additional details, refer to the VulnCheck Advisory on Fiverr Clone.

Workarounds

• Deploy a Web Application Firewall (WAF) with rules to filter XSS payloads in URL parameters
• Implement Content Security Policy (CSP) headers with script-src 'self' to prevent inline script execution
• Manually modify search-results.php to apply htmlspecialchars() or equivalent encoding to the keyword parameter before output

# Example Apache mod_security rule to block XSS in keyword parameter
SecRule ARGS:keyword "@rx <[^>]*script" "id:1001,phase:2,deny,status:403,msg:'XSS attempt blocked in keyword parameter'"