CVE-2023-27040
📋 TL;DR
Simple Image Gallery v1.0 contains a remote code execution vulnerability in the username parameter that allows attackers to execute arbitrary code on affected systems. This affects all installations of Simple Image Gallery v1.0 that are exposed to untrusted users. Attackers can gain complete control of vulnerable systems through this flaw.
💻 Affected Systems
- Simple Image Gallery
📦 What is this software?
Simple Image Gallery Web App by Simple Image Gallery Web App Project
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to install malware, steal data, pivot to other systems, or establish persistent backdoors.
Likely Case
Web server compromise leading to data theft, defacement, or use as part of botnets for further attacks.
If Mitigated
Limited impact with proper network segmentation and monitoring, though system integrity would still be compromised.
🎯 Exploit Status
Exploit code is publicly available and requires minimal technical skill to execute.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: N/A
Vendor Advisory: N/A
Restart Required: No
Instructions:
1. Immediately remove Simple Image Gallery v1.0 from all systems
2. Replace with alternative gallery software
3. No official patch exists for this version
🔧 Temporary Workarounds
Input Validation Filter
allAdd server-side input validation to sanitize username parameter
Implement proper input validation in PHP code to filter special characters
Web Application Firewall Rules
allBlock malicious payloads targeting the username parameter
Add WAF rule to block requests containing shell metacharacters in username parameter
🧯 If You Can't Patch
- Isolate affected systems from internet and critical internal networks
- Implement strict network monitoring and alerting for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check if Simple Image Gallery v1.0 is installed by examining web directory contents and version filesCheck Version:
Check for version.txt or similar files in the gallery installation directoryVerify Fix Applied:
Verify software has been completely removed and no gallery files remain📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to gallery login with shell metacharacters in username parameter
- System commands executed from web server process
Network Indicators:
- Outbound connections from web server to unusual destinations
- Sudden increase in web server resource usage
SIEM Query:
source="web_logs" AND uri="*/gallery/login*" AND username="*[;|&`$()]*"