CVE-2025-27019
📋 TL;DR
This critical vulnerability in Infinera MTC-9's remote shell service allows unauthenticated attackers to gain full system access via reverse shells using password-less accounts. It affects MTC-9 devices running specific firmware versions, enabling complete compromise of affected systems.
💻 Affected Systems
- Infinera MTC-9
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system takeover, data exfiltration, lateral movement to other systems, and persistent backdoor installation leading to operational disruption.
Likely Case
Unauthorized remote access to the device, configuration changes, credential harvesting, and potential use as a pivot point for network attacks.
If Mitigated
Limited impact if device is isolated, has strict network controls, and reverse shell attempts are blocked by security controls.
🎯 Exploit Status
Exploitation leverages password-less accounts and reverse shell activation, making it straightforward for attackers with network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: R23.0 or later
Vendor Advisory: https://www.cvcn.gov.it/cvcn/cve/CVE-2025-27019
Restart Required: Yes
Instructions:
1. Download R23.0+ firmware from Infinera support portal. 2. Backup current configuration. 3. Apply firmware update via management interface. 4. Reboot device. 5. Verify version with 'show version' command.
🔧 Temporary Workarounds
Disable Remote Shell Service
allCompletely disable the vulnerable RSH service if not required for operations
configure terminal
no service rsh
write memory
Network Access Control
allRestrict network access to MTC-9 management interfaces using firewall rules
🧯 If You Can't Patch
- Isolate affected devices in separate VLAN with strict firewall rules allowing only necessary traffic
- Implement network monitoring for reverse shell connections and unusual outbound connections
🔍 How to Verify
Check if Vulnerable:
Check firmware version with 'show version' command. If version is between R22.1.1.0275 and before R23.0, device is vulnerable.Check Version:
show versionVerify Fix Applied:
After patching, verify version is R23.0 or later with 'show version'. Test RSH service functionality if required.📡 Detection & Monitoring
Log Indicators:
- Unusual RSH service activations
- Failed authentication attempts to password-less accounts
- Reverse shell connection logs
Network Indicators:
- Unexpected outbound connections from MTC-9 devices
- RSH traffic on non-standard ports
- Reverse shell patterns in network traffic
SIEM Query:
source_ip=MTC-9 AND (protocol=RSH OR dest_port IN [514, 1023-65535])