CVE-2025-67906: MISP XSS Vulnerability in Workflows

CVE-2025-67906 Overview

CVE-2025-67906 is a Cross-Site Scripting (XSS) vulnerability affecting MISP (Malware Information Sharing Platform) versions prior to 2.5.28. The vulnerability exists in the app/View/Elements/Workflows/executionPath.ctp template file, which fails to properly sanitize user-controlled input in the workflow execution path component. This allows authenticated attackers to inject malicious scripts that execute in the context of other users' browsers, potentially leading to session hijacking, data theft, or unauthorized actions within the threat intelligence platform.

Critical Impact

Successful exploitation of this XSS vulnerability in MISP could allow attackers to compromise threat intelligence sharing operations, steal session tokens from security analysts, or manipulate shared threat data within organizations relying on MISP for collaborative security operations.

Affected Products

• MISP versions prior to 2.5.28
• MISP Workflow module with execution path visualization
• Organizations using MISP for threat intelligence sharing

Discovery Timeline

• 2025-12-15 - CVE-2025-67906 published to NVD
• 2025-12-21 - Last updated in NVD database

Technical Details for CVE-2025-67906

Vulnerability Analysis

This XSS vulnerability occurs due to insufficient input validation and output encoding in the workflow execution path visualization component of MISP. The executionPath.ctp CakePHP template file renders workflow execution data without properly escaping user-controllable content, allowing malicious JavaScript code to be injected and executed in the browsers of other authenticated MISP users.

The vulnerability requires low privileges to exploit (an authenticated user account) but has a changed scope, meaning the exploited vulnerability can affect resources beyond the vulnerable component. The potential impact includes complete compromise of confidentiality, integrity, and availability of user sessions and data accessible through the MISP interface.

MISP is widely deployed in security operations centers and threat intelligence sharing communities, making this vulnerability particularly concerning as it could be leveraged to compromise trusted threat data or gain access to sensitive indicators of compromise shared between organizations.

Root Cause

The root cause of CVE-2025-67906 is improper neutralization of input during web page generation (CWE-79). The executionPath.ctp template file directly renders workflow execution path data without adequate HTML entity encoding or JavaScript escaping. When user-supplied or workflow-derived data containing script tags or event handlers is processed by this template, the malicious content is rendered as executable code rather than being treated as plain text.

Attack Vector

The attack vector is network-based and requires user interaction. An authenticated attacker can craft a malicious workflow execution path containing JavaScript payloads. When other authenticated users view the workflow visualization that includes the attacker's malicious input, the injected script executes in their browser context. This could be leveraged to:

1. Steal session cookies and authentication tokens
2. Perform actions on behalf of the victim user
3. Modify or exfiltrate sensitive threat intelligence data
4. Propagate the attack to other MISP users through stored XSS

The vulnerability can be exploited by injecting malicious JavaScript through workflow path elements. When the executionPath.ctp template renders this data without proper sanitization, the script executes in victims' browsers. For detailed technical information, refer to the GitHub CVE-2025-67906 Repository and the MISP commit addressing this vulnerability.

Detection Methods for CVE-2025-67906

Indicators of Compromise

• Unusual JavaScript patterns or encoded script tags in workflow execution path data
• Unexpected network requests originating from the MISP web interface to external domains
• Session tokens appearing in server logs or being transmitted to unauthorized endpoints
• User reports of unexpected behavior when viewing workflow visualizations

Detection Strategies

• Monitor web application logs for requests containing potential XSS payloads targeting workflow-related endpoints
• Implement Content Security Policy (CSP) headers and monitor for CSP violation reports
• Deploy web application firewall (WAF) rules to detect and block common XSS attack patterns
• Review workflow execution path data for suspicious HTML or JavaScript content

Monitoring Recommendations

• Enable detailed access logging for MISP workflow components
• Configure alerting for anomalous client-side script execution patterns
• Monitor for unauthorized data exfiltration attempts from MISP user sessions
• Track changes to workflow configurations and execution paths for tampering indicators

How to Mitigate CVE-2025-67906

Immediate Actions Required

• Upgrade MISP to version 2.5.28 or later immediately
• Review workflow execution paths for any suspicious or malicious content
• Invalidate active user sessions and require re-authentication after patching
• Implement Content Security Policy headers to restrict script execution sources

Patch Information

MISP has released version 2.5.28 which addresses this XSS vulnerability. The fix is available in commit 1f39deb572da7ecb5855e30ff3cc8cbcaa0c1054. Organizations should review the version comparison between v2.5.27 and v2.5.28 to understand all changes included in the security update.

Workarounds

• Implement strict Content Security Policy headers to prevent inline script execution
• Deploy a web application firewall with XSS detection rules in front of MISP instances
• Restrict access to workflow visualization features to trusted administrators only
• Enable HTTPOnly and Secure flags on all session cookies to limit XSS impact

# Example CSP header configuration for Apache
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; frame-ancestors 'none';"

# Enable HTTPOnly and Secure cookie flags in MISP configuration
# Edit app/Config/core.php
# Configure::write('Session.cookie', 'MISP');
# Configure::write('Session.cookieHttpOnly', true);
# Configure::write('Security.cipherSeed', 'your-random-seed');