CVE-2025-56762 Overview
CVE-2025-56762 is a reflected Cross-Site Scripting (XSS) vulnerability affecting Paracrawl KeOPs v2. The flaw resides in the error.php script, which fails to properly sanitize user-supplied input before returning it in the HTTP response. An attacker can craft a malicious URL that, when visited by an authenticated or unauthenticated user, causes arbitrary JavaScript to execute in the victim's browser session. The issue is classified under [CWE-79] (Improper Neutralization of Input During Web Page Generation).
Critical Impact
Successful exploitation enables session hijacking, credential theft, and delivery of drive-by browser attacks against KeOPs users.
Affected Products
- Paracrawl KeOPs version 2
- The error.php component within the KeOPs web application
- Deployments exposing KeOPs error handling to untrusted networks
Discovery Timeline
- 2025-09-19 - CVE-2025-56762 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-56762
Vulnerability Analysis
The vulnerability is a reflected XSS flaw in the error.php endpoint of Paracrawl KeOPs v2. The script echoes request parameters back into the rendered HTML response without applying output encoding or input validation. When a victim follows a crafted link, the injected payload executes in the origin of the KeOPs application. Attackers can leverage this to steal session cookies, perform actions on behalf of the user, or pivot to further browser-based attacks. The public proof-of-concept is published in the GitHub CVE-2025-56762 PoC repository.
Root Cause
The root cause is missing output encoding in error.php. User-controlled data flows directly from HTTP request parameters into the HTML response body without HTML entity escaping or context-aware sanitization. This violates the secure coding practice of treating all client-supplied input as untrusted before reflection.
Attack Vector
Exploitation requires user interaction: a victim must click or be redirected to a crafted URL pointing at the vulnerable error.php endpoint. Because the attack occurs over the network with no privileges required, phishing and watering-hole delivery are practical vectors. The scope-changed impact allows the injected script to affect resources beyond the initial component, such as authenticated sessions on the same origin.
No verified exploitation code is reproduced here. See the Paracrawl KeOPs project and the public PoC repository for technical details.
Detection Methods for CVE-2025-56762
Indicators of Compromise
- HTTP requests to error.php containing script tags, event handlers such as onerror=, or URL-encoded JavaScript payloads
- Web server access logs showing unusual query strings referencing <script>, javascript:, or document.cookie
- Outbound requests from user browsers to unfamiliar domains shortly after visiting KeOPs URLs
Detection Strategies
- Deploy web application firewall (WAF) signatures that flag reflected XSS patterns in requests to error.php
- Review referrer and query-string fields in KeOPs access logs for injection payloads
- Correlate anomalous session activity, such as sudden cookie exfiltration or unexpected privileged actions, with recent visits to error pages
Monitoring Recommendations
- Enable verbose logging on the KeOPs web tier and forward events to a centralized analytics platform
- Alert on repeated 4xx or 5xx responses from error.php accompanied by encoded script content
- Monitor Content Security Policy (CSP) violation reports to identify script execution attempts
How to Mitigate CVE-2025-56762
Immediate Actions Required
- Restrict external access to the KeOPs application until sanitization is applied to error.php
- Apply HTML entity encoding to all reflected parameters using functions such as htmlspecialchars() with ENT_QUOTES and UTF-8 encoding
- Enforce a strict Content Security Policy that disallows inline scripts and untrusted script sources
Patch Information
No vendor advisory or official patch is listed in the NVD entry for CVE-2025-56762. Track the upstream Paracrawl KeOPs project for security-relevant commits and apply mitigations at the application or proxy layer until a fix is published.
Workarounds
- Wrap error.php behind an authenticating reverse proxy to reduce exposure to unauthenticated users
- Add a WAF rule that blocks requests containing script tags, javascript: URIs, or encoded payload variants targeting error.php
- Set the HttpOnly and Secure flags on session cookies to limit the impact of successful script injection
- Configure X-XSS-Protection, X-Content-Type-Options: nosniff, and a restrictive Content-Security-Policy header at the web server
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
