CVE-2025-1736
📋 TL;DR
This CVE describes an insufficient validation vulnerability in PHP's header handling that could allow attackers to manipulate HTTP headers. When user-supplied headers contain specific end-of-line characters, PHP may fail to send certain headers or misinterpret them, potentially leading to security bypasses or injection attacks. This affects PHP applications running vulnerable versions that process untrusted header input.
💻 Affected Systems
- PHP
📦 What is this software?
Ontap by Netapp
Php by Php
Php by Php
Php by Php
Php by Php
⚠️ Risk & Real-World Impact
Worst Case
HTTP response splitting leading to cache poisoning, session fixation, cross-site scripting (XSS), or security control bypass by manipulating HTTP headers.
Likely Case
Header manipulation causing unexpected application behavior, potential security control bypass, or limited information disclosure through header injection.
If Mitigated
Minimal impact if input validation and output encoding are properly implemented, though underlying vulnerability remains.
🎯 Exploit Status
Exploitation requires ability to control header values sent via PHP functions. No public exploit code identified at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: PHP 8.1.32, PHP 8.2.28, PHP 8.3.19, PHP 8.4.5
Vendor Advisory: https://github.com/php/php-src/security/advisories/GHSA-hgf5-96fm-v528
Restart Required: No
Instructions:
1. Identify PHP version with 'php -v'. 2. Update PHP using your package manager (apt, yum, etc.). 3. For compiled PHP: download patched version from php.net and recompile. 4. Restart web server (Apache, Nginx, etc.) to load new PHP version.
🔧 Temporary Workarounds
Input validation for headers
allValidate and sanitize all user-supplied header values before passing to PHP header functions
Web Application Firewall (WAF)
allDeploy WAF rules to detect and block malicious header patterns containing suspicious end-of-line characters
🧯 If You Can't Patch
- Implement strict input validation for all header-related user inputs
- Deploy network-level protections like WAF with header inspection capabilities
🔍 How to Verify
Check if Vulnerable:
Run 'php -v' and check if version falls within affected ranges: 8.1.0-8.1.31, 8.2.0-8.2.27, 8.3.0-8.3.18, 8.4.0-8.4.4Check Version:
php -v | head -1Verify Fix Applied:
After patching, run 'php -v' to confirm version is 8.1.32+, 8.2.28+, 8.3.19+, or 8.4.5+📡 Detection & Monitoring
Log Indicators:
- Unusual header patterns in web server logs
- Multiple failed header operations in PHP error logs
- Unexpected HTTP response codes from header manipulation
Network Indicators:
- Malformed HTTP headers in requests
- Suspicious end-of-line characters in header values
- Unexpected header injection patterns
SIEM Query:
source="web_server_logs" AND (header:*\r\n* OR header:*\n* OR header:*\r*) AND status_code=200