CVE-2024-31070 Overview
CVE-2024-31070 is an insecure default configuration vulnerability affecting Century Systems Co., Ltd. FutureNet NXR series, VXR series, and WXR series network routers. The vulnerability exists due to initialization of a resource with insecure default settings, which allows a remote unauthenticated attacker to access the telnet service without restriction. This flaw enables attackers to gain unauthorized network access to affected devices, potentially compromising network infrastructure and enabling further lateral movement within target environments.
Critical Impact
Remote unauthenticated attackers can access telnet service unlimitedly on affected FutureNet routers, potentially compromising network infrastructure and enabling unauthorized access to critical systems.
Affected Products
- Century Systems FutureNet NXR-1300 Firmware
- Century Systems FutureNet NXR-1200 Firmware
- Century Systems FutureNet NXR-650 Firmware
- Century Systems FutureNet NXR-530 Firmware
- Century Systems FutureNet NXR-G200 Firmware
- Century Systems FutureNet NXR-G180/L-CA Firmware
- Century Systems FutureNet NXR-G120 Firmware
- Century Systems FutureNet NXR-G110 Firmware
- Century Systems FutureNet NXR-G100 Firmware
- Century Systems FutureNet NXR-G060 Firmware
- Century Systems FutureNet NXR-G050 Firmware
- Century Systems FutureNet NXR-610X Firmware
- Century Systems FutureNet NXR-350/C Firmware
- Century Systems FutureNet NXR-230/C Firmware
- Century Systems FutureNet NXR-160/LW Firmware
- Century Systems FutureNet NXR-155/C Firmware
- Century Systems FutureNet NXR-130/C Firmware
- Century Systems FutureNet NXR-125/CX Firmware
- Century Systems FutureNet NXR-120/C Firmware
- Century Systems FutureNet VXR-X64
- Century Systems FutureNet VXR-X86
- Century Systems FutureNet WXR-250 Firmware
Discovery Timeline
- July 17, 2024 - CVE-2024-31070 published to NVD
- November 21, 2024 - Last updated in NVD database
Technical Details for CVE-2024-31070
Vulnerability Analysis
This vulnerability is classified as CWE-1188 (Initialization of a Resource with an Insecure Default). The affected FutureNet router devices ship with default configurations that do not adequately restrict access to the telnet service. When deployed without proper hardening, these devices expose telnet management interfaces to remote attackers without requiring authentication.
The telnet protocol transmits data in plaintext, making any sessions vulnerable to interception. Combined with the unrestricted access enabled by this vulnerability, attackers can connect to affected routers, potentially enumerate device configurations, extract credentials, modify routing tables, or use the compromised device as a pivot point for further network attacks.
Network edge devices like these routers are particularly high-value targets as they often serve as gateways between internal networks and external systems. Compromise of such devices can lead to widespread network infiltration and data exfiltration.
Root Cause
The root cause of this vulnerability lies in the firmware's default initialization process, which fails to implement secure-by-default settings for the telnet service. The telnet daemon starts with permissive access controls that do not require authentication or limit connection attempts, allowing any network-accessible attacker to establish sessions without credentials.
Attack Vector
The attack vector is network-based and requires no authentication or user interaction. An attacker with network access to the management interface of an affected device can directly connect to the telnet service on port 23 (default). Once connected, the attacker can interact with the device's command-line interface and potentially execute administrative commands.
Attack scenarios include:
- Scanning for exposed FutureNet devices on the internet or internal networks
- Connecting directly to the telnet service without credentials
- Extracting configuration data including network topology and credentials
- Modifying device configurations to enable persistent access
- Using the compromised router to intercept or redirect network traffic
Detection Methods for CVE-2024-31070
Indicators of Compromise
- Unexpected telnet connections (port 23) to FutureNet router management interfaces from external or unauthorized IP addresses
- Unusual configuration changes on affected devices without corresponding administrative activity logs
- New or modified access control lists, routing configurations, or user accounts on router devices
- Network traffic anomalies suggesting data exfiltration or command-and-control communication originating from router devices
Detection Strategies
- Monitor network traffic for telnet connections to FutureNet router devices, especially from untrusted networks
- Implement network intrusion detection rules to alert on unauthorized management interface access attempts
- Conduct regular configuration audits of affected devices to identify unauthorized changes
- Deploy network monitoring to detect unusual traffic patterns from router IP addresses
Monitoring Recommendations
- Configure SIEM systems to alert on telnet connection attempts to critical infrastructure devices
- Implement network segmentation monitoring to detect lateral movement from compromised routers
- Enable and review authentication logs on affected devices where possible
- Establish baseline network behavior for router devices to identify anomalies
How to Mitigate CVE-2024-31070
Immediate Actions Required
- Disable telnet service on all affected FutureNet devices and use SSH for remote management instead
- Implement network access control lists to restrict management interface access to authorized IP addresses only
- Isolate affected router management interfaces on dedicated management VLANs not accessible from untrusted networks
- Review device configurations for signs of unauthorized access or modification
- Apply firmware updates from Century Systems as they become available
Patch Information
Century Systems has released security advisories addressing this vulnerability. Organizations should consult the vendor advisories for specific firmware versions that remediate this issue:
Workarounds
- Disable the telnet service entirely and transition to SSH for all remote management operations
- Implement strict firewall rules to block port 23 access from all untrusted networks
- Deploy network access control (NAC) solutions to restrict which devices can communicate with router management interfaces
- Configure strong authentication mechanisms and ensure default credentials are changed on all devices
- Consider deploying a jump host or bastion server for all router management access
# Example: Restrict management access via ACL (adjust syntax per device model)
# Consult Century Systems documentation for device-specific commands
# Disable telnet service (example conceptual command)
no telnet-server enable
# Enable SSH as replacement
ssh-server enable
# Restrict management access to specific subnet
access-list management permit 10.0.0.0/24
access-list management deny any
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
