CVE-2021-34710
📋 TL;DR
This vulnerability in Cisco ATA 190 Series Analog Telephone Adapters allows attackers to execute arbitrary commands on affected devices through command injection. Successful exploitation could lead to remote code execution or denial of service. Organizations using these devices for VoIP telephony are affected.
💻 Affected Systems
- Cisco ATA 190 Series Analog Telephone Adapter
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full device compromise allowing attacker to execute arbitrary code, pivot to internal networks, and maintain persistent access.
Likely Case
Remote code execution leading to device takeover, service disruption, or use as foothold for lateral movement.
If Mitigated
Limited impact if devices are isolated in separate VLANs with strict network segmentation and access controls.
🎯 Exploit Status
Command injection vulnerabilities typically have low exploitation complexity. No public exploit code has been observed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 11.2.1 and later
Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ata19x-multivuln-A4J57F3
Restart Required: Yes
Instructions:
1. Download firmware version 11.2.1 or later from Cisco.com. 2. Access device web interface. 3. Navigate to Administration > Upgrade. 4. Upload new firmware file. 5. Wait for upgrade to complete. 6. Device will automatically reboot.
🔧 Temporary Workarounds
Network Segmentation
allIsolate ATA devices in separate VLANs with strict firewall rules limiting access to management interfaces.
Access Control Lists
allImplement ACLs to restrict access to ATA management interfaces from untrusted networks.
access-list 101 deny ip any host <ATA_IP>
access-list 101 permit ip any any
🧯 If You Can't Patch
- Implement strict network segmentation to isolate ATA devices from untrusted networks
- Deploy intrusion detection/prevention systems to monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check firmware version via web interface: Login > Status > System Information > Firmware VersionCheck Version:
Check web interface or use SNMP query to device firmware versionVerify Fix Applied:
Verify firmware version is 11.2.1 or later in System Information page📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in device logs
- Multiple failed authentication attempts
- Unexpected configuration changes
Network Indicators:
- Unusual traffic patterns to/from ATA devices
- Suspicious HTTP requests to management interface
- Unexpected outbound connections from ATA devices
SIEM Query:
source="ata190" AND (event="command_execution" OR event="configuration_change")