CVE-2024-8926
📋 TL;DR
This CVE allows command injection in PHP on Windows systems with specific non-standard codepage configurations, bypassing previous CVE-2024-4577 fixes. Attackers can execute arbitrary PHP code, reveal source code, or pass malicious options to PHP binaries. Affects PHP 8.1-8.3 on Windows with certain codepage settings.
💻 Affected Systems
- PHP
📦 What is this software?
Php by Php
Php by Php
Php by Php
⚠️ Risk & Real-World Impact
Worst Case
Full remote code execution leading to complete server compromise, data exfiltration, and lateral movement within the network.
Likely Case
Arbitrary PHP code execution allowing source code disclosure, file system access, and potential web shell installation.
If Mitigated
Limited impact with proper network segmentation, WAF rules, and restricted PHP execution environments.
🎯 Exploit Status
Exploitation requires specific Windows codepage configurations and knowledge of CVE-2024-4577 bypass techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: PHP 8.1.30, 8.2.24, 8.3.12
Vendor Advisory: https://github.com/php/php-src/security/advisories/GHSA-p99j-rfp4-xqvq
Restart Required: Yes
Instructions:
1. Download latest PHP version for affected branch. 2. Replace existing PHP installation. 3. Restart web server/service. 4. Test application functionality.
🔧 Temporary Workarounds
Disable vulnerable codepages
windowsConfigure Windows to use standard codepages that don't trigger the Best Fit behavior bypass.
Set system locale to standard UTF-8 or compatible codepage
Web Application Firewall rules
allBlock requests containing PHP command injection patterns and unusual codepage indicators.
Configure WAF to block patterns: -d allow_url_include=1, -d auto_prepend_file=php://input, etc.
🧯 If You Can't Patch
- Implement strict input validation and sanitization for all PHP parameters
- Use network segmentation to isolate PHP servers and implement strict egress filtering
🔍 How to Verify
Check if Vulnerable:
Check PHP version with php -v and verify if running affected versions on Windows with non-standard codepages.Check Version:
php -vVerify Fix Applied:
Confirm PHP version is 8.1.30+, 8.2.24+, or 8.3.12+ and test with known exploitation patterns.📡 Detection & Monitoring
Log Indicators:
- Unusual PHP command-line arguments in web logs
- Requests with -d parameters containing php:// wrappers
- Multiple failed exploitation attempts
Network Indicators:
- HTTP requests with PHP CLI parameters in query strings or headers
- Unusual codepage-related headers
SIEM Query:
source="web_logs" AND ("-d" OR "allow_url_include" OR "auto_prepend_file") AND dest_port=80