CVE-2024-7330
📋 TL;DR
This CVE describes a Server-Side Request Forgery (SSRF) vulnerability in YouDianCMS 7 that allows attackers to manipulate the curl_exec function to make unauthorized requests from the vulnerable server. Attackers can exploit this remotely to potentially access internal systems or services. All users running YouDianCMS 7 are affected by this critical vulnerability.
💻 Affected Systems
- YouDianCMS
📦 What is this software?
Youdiancms by Youdiancms
⚠️ Risk & Real-World Impact
Worst Case
Attackers could use the vulnerable server as a proxy to access internal network resources, perform port scanning, interact with cloud metadata services, or chain with other vulnerabilities to achieve remote code execution.
Likely Case
Attackers will exploit this to make unauthorized requests to internal services, potentially accessing sensitive data or performing reconnaissance on internal networks.
If Mitigated
With proper network segmentation and egress filtering, the impact is limited to the server making unauthorized external requests, though internal network access may still be possible.
🎯 Exploit Status
The exploit has been publicly disclosed and requires minimal technical skill to execute. Attackers can trigger the vulnerability by manipulating URL parameters sent to the vulnerable function.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: No
Instructions:
No official patch is available as the vendor did not respond to disclosure. Consider upgrading to a different CMS or implementing workarounds.
🔧 Temporary Workarounds
Input Validation and URL Whitelisting
allImplement strict input validation for URL parameters and restrict curl_exec to only allow requests to trusted domains.
Modify /App/Core/Extend/Function/ydLib.php to validate URL parameters before curl_exec
Disable Vulnerable Function
allTemporarily disable or restrict access to the vulnerable function until a proper fix is available.
Comment out or modify the curl_exec call in ydLib.php to return an error for unauthorized requests
🧯 If You Can't Patch
- Implement network-level restrictions to limit outbound connections from the server to only necessary services
- Deploy a Web Application Firewall (WAF) with SSRF protection rules to block malicious requests
🔍 How to Verify
Check if Vulnerable:
Check if YouDianCMS version 7 is installed and review the /App/Core/Extend/Function/ydLib.php file for the curl_exec function with URL parameter handling.Check Version:
Check YouDianCMS configuration files or admin panel for version informationVerify Fix Applied:
Test that URL parameter manipulation no longer allows unauthorized requests through the curl_exec function.📡 Detection & Monitoring
Log Indicators:
- Unusual outbound HTTP requests from the server, especially to internal IP addresses or cloud metadata endpoints
- Multiple failed or unusual curl requests in application logs
Network Indicators:
- Unexpected outbound HTTP traffic from the server to unusual destinations
- Requests to internal network addresses from the web server
SIEM Query:
source="web_server_logs" AND (url_contains="curl_exec" OR url_contains="ydLib.php") AND (dest_ip=private_ip_range OR dest_ip=169.254.169.254)