CVE-2020-28993
📋 TL;DR
CVE-2020-28993 is a directory traversal vulnerability in ATX miniCMTS200a Broadband Gateway and Pico CMTS devices that allows unauthenticated attackers to retrieve administrator credentials via malicious POST requests. This affects organizations using these specific ATX networking devices for broadband services. Successful exploitation gives attackers administrative access to the gateway.
💻 Affected Systems
- ATX miniCMTS200a Broadband Gateway
- ATX Pico CMTS
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the broadband gateway allowing attackers to reconfigure network settings, intercept traffic, deploy malware, or use the device as an attack pivot point into the internal network.
Likely Case
Attackers gain administrative credentials and take control of the gateway to monitor or manipulate network traffic, potentially leading to data interception or service disruption.
If Mitigated
Attackers can still retrieve credentials but cannot use them due to network segmentation, strong authentication controls, or immediate credential rotation.
🎯 Exploit Status
Exploit code is publicly available on Exploit-DB (ID: 49124) and requires minimal technical skill to execute. The attack can be automated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not publicly available
Restart Required: No
Instructions:
Contact ATX support for firmware updates or replacement options. No official patch information is publicly documented.
🔧 Temporary Workarounds
Network Segmentation
allIsolate affected devices from untrusted networks and restrict access to management interfaces
Access Control Lists
allImplement firewall rules to restrict access to device management interfaces
🧯 If You Can't Patch
- Immediately change all administrator credentials and implement strong password policies
- Monitor network traffic to/from affected devices for suspicious POST requests to credential-related endpoints
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface or CLI. If version is 2.0 or earlier, device is vulnerable.Check Version:
Check via web interface at http://[device-ip]/status or consult device documentationVerify Fix Applied:
Verify firmware version is above 2.0 or test with controlled exploit attempt (not recommended in production).📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to credential-related paths
- Multiple failed login attempts followed by successful login from new IP
Network Indicators:
- POST requests to paths containing directory traversal sequences (../)
- Credential retrieval attempts from unauthorized sources
SIEM Query:
source_ip=* AND (http_method=POST AND (uri="*../*" OR uri="*credentials*" OR uri="*admin*"))