CVE-2020-29058
📋 TL;DR
This vulnerability allows attackers to retrieve cleartext web-server credentials by making specific CGI requests to affected CDATA optical line terminal devices. Attackers can gain administrative access to the web interface, potentially compromising the entire network device. Organizations using the listed CDATA OLT models are affected.
💻 Affected Systems
- CDATA 72408A
- 9008A
- 9016A
- 92408A
- 92416A
- 9288
- 97016
- 97024P
- 97028P
- 97042P
- 97084P
- 97168P
- FD1002S
- FD1104
- FD1104B
- FD1104S
- FD1104SN
- FD1108S
- FD1204S-R2
- FD1204SN
- FD1204SN-R2
- FD1208S-R2
- FD1216S-R1
- FD1608GS
- FD1608SN
- FD1616GS
- FD1616SN
- FD8000
📦 What is this software?
9288 Firmware by Cdatatec
9288 Firmware by Cdatatec
9288 Firmware by Cdatatec
9288 Firmware by Cdatatec
⚠️ Risk & Real-World Impact
Worst Case
Full device compromise leading to network disruption, credential harvesting, lateral movement to connected networks, and persistent backdoor installation.
Likely Case
Unauthorized administrative access to the web interface, configuration changes, service disruption, and credential theft.
If Mitigated
Limited impact if devices are behind firewalls with strict access controls and network segmentation.
🎯 Exploit Status
Exploitation requires simple HTTP requests to specific CGI endpoints. Public research includes detailed exploitation methods.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No official vendor advisory found
Restart Required: No
Instructions:
Contact CDATA vendor for firmware updates. No official patch information available at time of analysis.
🔧 Temporary Workarounds
Block CGI Access
linuxRestrict access to /opt/lighttpd/web/cgi/ paths via firewall or web server configuration
iptables -A INPUT -p tcp --dport 80 -m string --string "/opt/lighttpd/web/cgi/" --algo bm -j DROP
iptables -A INPUT -p tcp --dport 443 -m string --string "/opt/lighttpd/web/cgi/" --algo bm -j DROP
Network Segmentation
allIsolate affected devices in separate VLANs with strict access controls
🧯 If You Can't Patch
- Implement strict network access controls to limit device access to authorized administrators only
- Monitor network traffic for suspicious CGI requests and implement intrusion detection rules
🔍 How to Verify
Check if Vulnerable:
Test by making HTTP GET requests to CGI endpoints like /cgi-bin/ endpoints on port 80/443 and checking for credential disclosure in responsesCheck Version:
Check device web interface or console for firmware version informationVerify Fix Applied:
Verify CGI endpoints no longer return cleartext credentials when accessed📡 Detection & Monitoring
Log Indicators:
- Unusual access to CGI scripts
- Multiple failed authentication attempts followed by CGI access
- Administrative login from unexpected IP addresses
Network Indicators:
- HTTP requests to /opt/lighttpd/web/cgi/ paths
- Traffic patterns showing credential harvesting
SIEM Query:
source="web_server" AND (uri="*cgi*" OR uri="*/opt/lighttpd/web/cgi/*") AND status=200