CVE-2023-49257
📋 TL;DR
This vulnerability allows authenticated users to upload arbitrary CGI-compatible files through a certificate upload utility and execute them with root privileges. It affects systems running vulnerable versions of software with this upload functionality. Attackers can achieve remote code execution as the root user.
💻 Affected Systems
- Software with certificate upload utility vulnerable to CWE-732
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with root-level access, allowing attackers to install persistent backdoors, exfiltrate sensitive data, or pivot to other systems.
Likely Case
Unauthorized remote code execution leading to data theft, service disruption, or lateral movement within the network.
If Mitigated
Limited impact if proper access controls and file validation are implemented, though risk remains if authentication is bypassed.
🎯 Exploit Status
Exploitation requires authenticated access but is straightforward once credentials are obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor advisory for specific patched versions
Vendor Advisory: https://cert.pl/en/posts/2024/01/CVE-2023-49253/
Restart Required: Yes
Instructions:
1. Identify affected software version. 2. Apply vendor-provided patch or update to fixed version. 3. Restart the service or system as required. 4. Verify the fix is applied.
🔧 Temporary Workarounds
Disable certificate upload utility
allTemporarily disable the vulnerable upload feature to prevent exploitation.
# Check software configuration for upload settings
# Disable or restrict upload functionality per vendor docs
Implement file validation
allAdd server-side validation to reject non-certificate files in uploads.
# Configure web server or application to validate file types
# Use allowlists for accepted file extensions
🧯 If You Can't Patch
- Restrict access to the upload utility using network segmentation or firewall rules.
- Implement strict authentication and monitoring for upload activities.
🔍 How to Verify
Check if Vulnerable:
Review software version and configuration; test if authenticated users can upload and execute arbitrary CGI files.Check Version:
# Run software-specific command to check version, e.g., 'software --version'Verify Fix Applied:
After patching, attempt to upload a test CGI file; execution should be blocked or fail.📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads via certificate utility
- Execution of unexpected CGI scripts
- Authentication logs from suspicious IPs
Network Indicators:
- HTTP POST requests to upload endpoints with non-certificate files
- Outbound connections from the system post-upload
SIEM Query:
source="web_logs" AND (url_path="/certificate_upload" AND file_extension!=".crt")