CVE-2025-14807: IBM InfoSphere Information Server XSS Flaw

CVE-2025-14807 Overview

IBM InfoSphere Information Server versions 11.7.0.0 through 11.7.1.6 is vulnerable to HTTP header injection due to improper validation of input by the HOST headers. This vulnerability could allow an attacker to conduct various attacks against the vulnerable system, including cross-site scripting (XSS), cache poisoning, or session hijacking.

Critical Impact

Attackers can inject malicious HTTP headers to manipulate web application behavior, potentially leading to cross-site scripting attacks, cache poisoning, or session hijacking of authenticated users.

Affected Products

• IBM InfoSphere Information Server 11.7.0.0 through 11.7.1.6
• IBM AIX (all supported versions running affected InfoSphere versions)
• Linux Kernel-based systems running affected InfoSphere versions
• Microsoft Windows systems running affected InfoSphere versions

Discovery Timeline

• 2026-03-25 - CVE-2025-14807 published to NVD
• 2026-03-26 - Last updated in NVD database

Technical Details for CVE-2025-14807

Vulnerability Analysis

This HTTP header injection vulnerability (CWE-644: Improper Neutralization of HTTP Headers for Scripting Syntax) exists in IBM InfoSphere Information Server's handling of HOST headers. The application fails to properly validate and sanitize user-controlled input in HTTP HOST headers before processing them, allowing attackers to inject arbitrary header content.

The vulnerability is network-accessible without requiring authentication or user interaction, making it exploitable by remote attackers. The impact includes potential compromise of data confidentiality and integrity, though system availability is not directly affected.

Root Cause

The root cause stems from improper neutralization of HTTP headers for scripting syntax. IBM InfoSphere Information Server does not adequately validate or sanitize the HOST header values received in HTTP requests. This allows malicious actors to craft specially formatted HOST headers containing injected content that the server processes without proper escaping or validation.

Attack Vector

The attack is conducted over the network by sending crafted HTTP requests containing malicious HOST header values to the vulnerable InfoSphere Information Server instance. An attacker does not require any privileges or authentication to exploit this vulnerability.

The injected headers can be leveraged to:

1. Cross-Site Scripting (XSS): Inject malicious scripts that execute in the context of victim browsers when the manipulated response is rendered
2. Cache Poisoning: Manipulate cached responses to serve malicious content to other users
3. Session Hijacking: Redirect or manipulate session-related headers to compromise user sessions

The attack exploits the trust the application places in the HOST header without proper validation, allowing the attacker to influence application behavior and response generation.

Detection Methods for CVE-2025-14807

Indicators of Compromise

• Unusual or malformed HOST headers in HTTP request logs containing encoded characters, newline sequences (\r\n), or unexpected values
• HTTP responses containing injected headers not generated by the application
• Evidence of cache poisoning with responses containing unexpected content for cached URLs
• Session anomalies indicating potential hijacking attempts

Detection Strategies

• Monitor web server and application logs for HTTP requests with anomalous HOST header values, particularly those containing special characters or encoding
• Implement web application firewall (WAF) rules to detect and block requests with malformed or suspicious HOST headers
• Review InfoSphere Information Server logs for unusual patterns indicating header injection attempts
• Deploy network intrusion detection signatures targeting HTTP header injection attack patterns

Monitoring Recommendations

• Enable detailed HTTP request logging on InfoSphere Information Server and upstream load balancers/proxies
• Configure SIEM alerts for patterns consistent with HTTP header injection attempts
• Monitor for unexpected changes in cached content that may indicate successful cache poisoning
• Track session anomalies and authentication events for signs of session hijacking

How to Mitigate CVE-2025-14807

Immediate Actions Required

• Apply the security patch from IBM as soon as possible for all affected InfoSphere Information Server installations
• Implement WAF rules to filter and validate HOST headers before they reach the application
• Review and audit current InfoSphere Information Server configurations for any exposed instances
• Consider restricting network access to InfoSphere Information Server to trusted networks only until patching is complete

Patch Information

IBM has released a security update to address this vulnerability. Administrators should consult the IBM Support Page for detailed patch information and installation instructions. Apply the appropriate fix pack to upgrade InfoSphere Information Server beyond version 11.7.1.6.

Workarounds

• Deploy a web application firewall (WAF) or reverse proxy configured to strictly validate and sanitize HOST headers before forwarding requests
• Configure upstream proxies or load balancers to override or normalize the HOST header with a known-good value
• Implement network-level access controls to limit exposure of InfoSphere Information Server to trusted IP ranges
• Monitor for exploitation attempts while planning the patch deployment

# Example: Apache reverse proxy configuration to normalize HOST header
<VirtualHost *:443>
    ServerName infosphere.example.com
    
    # Force HOST header to known-good value
    RequestHeader set Host "infosphere.example.com"
    
    # Block requests with suspicious HOST header patterns
    RewriteEngine On
    RewriteCond %{HTTP_HOST} !^infosphere\.example\.com$ [NC]
    RewriteRule .* - [F,L]
    
    ProxyPass / http://infosphere-backend:9443/
    ProxyPassReverse / http://infosphere-backend:9443/
</VirtualHost>