CVE-2020-21452
📋 TL;DR
This is a critical unauthenticated file upload vulnerability in Uniview ISC2500-S surveillance systems that allows attackers to upload arbitrary malicious files to the device. Attackers can achieve remote code execution by uploading webshells or other malicious payloads. All systems running vulnerable versions of this software are affected.
💻 Affected Systems
- Uniview ISC2500-S
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise leading to attacker gaining full control of the surveillance system, accessing camera feeds, pivoting to internal networks, and establishing persistent backdoors.
Likely Case
Remote code execution allowing attackers to deploy webshells, steal credentials, manipulate surveillance footage, or use the device as a foothold for further attacks.
If Mitigated
Limited impact if proper network segmentation, web application firewalls, and file upload restrictions are in place.
🎯 Exploit Status
Simple HTTP POST request to the vulnerable endpoint with malicious file upload. Public GitHub repositories contain exploit code.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not publicly available
Restart Required: No
Instructions:
Contact Uniview for security patches and firmware updates. Check vendor support portal for latest security bulletins.
🔧 Temporary Workarounds
Network Access Control
linuxBlock external access to the vulnerable endpoint using firewall rules
iptables -A INPUT -p tcp --dport 80 -m string --string "/Interface/DevManage/EC.php" --algo bm -j DROP
iptables -A INPUT -p tcp --dport 443 -m string --string "/Interface/DevManage/EC.php" --algo bm -j DROP
Web Application Firewall
allImplement WAF rules to block requests to the vulnerable endpoint
ModSecurity rule: SecRule REQUEST_URI "@contains /Interface/DevManage/EC.php" "id:1001,phase:1,deny,status:403,msg:'Block Uniview CVE-2020-21452 exploit'"
🧯 If You Can't Patch
- Isolate the device on a dedicated VLAN with strict firewall rules allowing only necessary traffic
- Implement network monitoring and IDS/IPS rules to detect exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Attempt to access https://[device-ip]/Interface/DevManage/EC.php?cmd=upload and check if endpoint responds. Test with controlled file upload if possible.Check Version:
Check web interface footer or system information page for firmware version. SSH/Telnet access may provide version info via 'uname -a' or similar commands.Verify Fix Applied:
Verify endpoint is no longer accessible or properly validates file uploads. Test with malicious file upload attempts that should be rejected.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /Interface/DevManage/EC.php with file upload parameters
- Unusual file creation in web directories
- Webshell-like file names (e.g., .php, .jsp, .asp files) in upload directories
Network Indicators:
- HTTP traffic to vulnerable endpoint with file upload content
- POST requests with multipart/form-data to the specific vulnerable path
SIEM Query:
source="web_server" AND (url="/Interface/DevManage/EC.php" OR url CONTAINS "EC.php") AND method="POST" AND size>100000