CVE-2024-39374: Markoni-d Firmware Auth Bypass Vulnerability

CVE-2024-39374 Overview

CVE-2024-39374 is a critical hardcoded credentials vulnerability affecting TELSAT marKoni FM Transmitters. The vulnerability allows an attacker to exploit a hidden admin account that can be accessed through the use of hard-coded credentials embedded in the device firmware. This type of security flaw (CWE-798) represents a serious configuration and design weakness that bypasses normal authentication mechanisms entirely.

FM transmitters are critical components in broadcast infrastructure, and unauthorized access could allow attackers to manipulate broadcast signals, disrupt communications, or use the compromised devices as a pivot point for further network attacks.

Critical Impact

Attackers can gain full administrative access to TELSAT marKoni FM Transmitters using hard-coded credentials, potentially compromising broadcast infrastructure and enabling complete device takeover.

Affected Products

• Markoni Markoni-D (Compact) Firmware - All versions
• Markoni Markoni-DH (Exciter+Amplifiers) Firmware - All versions
• TELSAT marKoni FM Transmitter hardware devices

Discovery Timeline

• 2024-06-27 - CVE-2024-39374 published to NVD
• 2024-06-27 - CISA released ICS Advisory ICSA-24-179-01
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2024-39374

Vulnerability Analysis

This vulnerability stems from the presence of a hidden administrative account with hard-coded credentials within the TELSAT marKoni FM Transmitter firmware. Hard-coded credentials represent one of the most severe classes of authentication vulnerabilities because they cannot be changed by end users and provide a consistent, reliable attack vector once discovered.

The network-accessible nature of this vulnerability means that any attacker who can reach the device's management interface over the network can attempt authentication using the hard-coded credentials. No user interaction is required, and the attack complexity is low since the credentials are static and embedded in the firmware.

Successful exploitation grants the attacker full administrative privileges over the FM transmitter, enabling them to modify broadcast parameters, update firmware with malicious code, disrupt broadcasting operations, or leverage the compromised device for lateral movement within the network.

Root Cause

The root cause is the inclusion of hard-coded administrative credentials (CWE-798: Use of Hard-coded Credentials) in the device firmware. This design flaw likely originated from development or debugging accounts that were never removed before production deployment. Hard-coded credentials are particularly dangerous in embedded systems and IoT devices where firmware updates are infrequent and users may lack the ability to change default authentication mechanisms.

Attack Vector

The vulnerability is exploitable over the network without requiring prior authentication or user interaction. An attacker with network access to the device's management interface can authenticate using the embedded credentials to gain administrative control.

The attack flow typically involves:

1. Identifying TELSAT marKoni FM Transmitters exposed on a network through port scanning or service enumeration
2. Accessing the device's web-based or command-line management interface
3. Authenticating using the hard-coded administrator credentials
4. Gaining full administrative access to modify device configuration, firmware, or broadcast parameters

Since no exploit code examples are available from verified sources, organizations should refer to the CISA ICS Advisory ICSA-24-179-01 for detailed technical information about this vulnerability.

Detection Methods for CVE-2024-39374

Indicators of Compromise

• Unexpected administrative logins to marKoni FM Transmitter management interfaces
• Authentication events using the hidden administrative account
• Unauthorized configuration changes to transmitter settings or broadcast parameters
• Unusual network traffic patterns to/from FM transmitter devices
• Firmware modification attempts or unexpected firmware versions

Detection Strategies

• Monitor authentication logs on marKoni FM Transmitters for access attempts using the hidden admin account
• Implement network intrusion detection rules to identify connections to FM transmitter management ports from unauthorized sources
• Deploy anomaly detection to identify unusual administrative activity patterns on broadcast infrastructure
• Configure SIEM alerts for successful authentications to critical broadcast equipment outside normal maintenance windows

Monitoring Recommendations

• Establish baseline behavior for administrative access to FM transmitters and alert on deviations
• Implement continuous asset discovery to identify all marKoni FM Transmitters in your environment
• Monitor network segments containing broadcast equipment for unauthorized access attempts
• Review audit logs regularly for signs of credential abuse or unauthorized configuration changes

How to Mitigate CVE-2024-39374

Immediate Actions Required

• Isolate affected TELSAT marKoni FM Transmitters from direct internet exposure using network segmentation
• Restrict network access to device management interfaces to authorized administrative workstations only
• Implement firewall rules to limit access to management ports from trusted IP addresses only
• Contact TELSAT/Markoni for firmware updates that address the hard-coded credentials vulnerability
• Conduct an audit to identify all affected devices in your environment

Patch Information

Organizations should consult the CISA ICS Advisory ICSA-24-179-01 for the latest vendor patch information and recommended mitigations. Contact TELSAT/Markoni directly for firmware updates that remove or disable the hard-coded administrative account.

Workarounds

• Deploy network access control lists (ACLs) to restrict management interface access to specific authorized IP addresses
• Place affected FM transmitters behind a VPN or jump host requiring separate authentication
• Implement 802.1X network authentication to limit physical network access to authorized devices
• Monitor for and alert on any access attempts to the affected devices' management interfaces
• Consider deploying a web application firewall (WAF) in front of web-based management interfaces if applicable

# Example network segmentation using iptables
# Restrict access to management interface (adjust ports as needed)
iptables -A INPUT -p tcp --dport 80 -s 192.168.100.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 192.168.100.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP