CVE-2025-36397
📋 TL;DR
IBM Application Gateway versions 23.10 through 25.09 are vulnerable to HTML injection, allowing attackers to inject malicious HTML that executes in users' browsers. This affects organizations using these versions of IBM Application Gateway, potentially compromising users who access the vulnerable interface.
💻 Affected Systems
- IBM Application Gateway
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could inject malicious scripts that steal session cookies, redirect users to phishing sites, or perform actions on behalf of authenticated users, potentially leading to account compromise or data theft.
Likely Case
Attackers inject malicious HTML/JavaScript to perform session hijacking, credential theft, or defacement of the application interface.
If Mitigated
With proper input validation and output encoding, the injected content would be rendered as plain text rather than executable code, preventing exploitation.
🎯 Exploit Status
HTML injection typically requires minimal technical skill and can be exploited through web requests.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 25.09 with fix or later versions
Vendor Advisory: https://www.ibm.com/support/pages/node/7256857
Restart Required: Yes
Instructions:
1. Review IBM advisory. 2. Apply the latest fix pack for IBM Application Gateway 25.09 or upgrade to a version beyond 25.09. 3. Restart the application gateway service.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation to reject or sanitize HTML content in user inputs.
Output Encoding
allEnsure all user-controlled data is properly encoded before being rendered in HTML responses.
🧯 If You Can't Patch
- Implement a web application firewall (WAF) with HTML injection protection rules.
- Restrict access to the vulnerable interface to trusted networks only.
🔍 How to Verify
Check if Vulnerable:
Check IBM Application Gateway version via administrative interface or configuration files. If version is between 23.10 and 25.09 inclusive, it is vulnerable.Check Version:
Check version in IBM Application Gateway admin console or configuration files (exact command varies by deployment).Verify Fix Applied:
Verify the version is updated to 25.09 with fix or later, and test that HTML injection attempts are properly sanitized.📡 Detection & Monitoring
Log Indicators:
- Unusual HTML/script patterns in user input logs
- Multiple failed injection attempts in web logs
Network Indicators:
- HTTP requests containing suspicious HTML tags or script elements to the application gateway
SIEM Query:
Search for web requests containing patterns like '<script>', 'javascript:', or HTML entities to the IBM Application Gateway endpoint.