CVE-2024-23690 in FVS336Gv3
Summary
by MITRE • 02/04/2025
The end-of-life Netgear FVS336Gv2 and FVS336Gv3 are affected by a command injection vulnerability in the Telnet interface. An authenticated and remote attacker can execute arbitrary OS commands as root over Telnet by sending crafted "util backup_configuration" commands.
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Analysis
by VulDB Data Team • 11/22/2025
The CVE-2024-23690 vulnerability represents a critical command injection flaw affecting legacy Netgear FVS336Gv2 and FVS336Gv3 firewall appliances that have reached end-of-life status. These devices operate with outdated firmware and lack current security updates, making them particularly susceptible to exploitation. The vulnerability specifically targets the Telnet interface, which remains enabled on these devices despite being deprecated for security reasons. This presents a significant risk as Telnet transmits credentials and commands in plaintext, creating an ideal environment for attackers to gain unauthorized access and execute malicious operations.
The technical exploitation of this vulnerability occurs through the "util backup_configuration" command within the Telnet interface. When an authenticated attacker sends specifically crafted commands to this interface, the system fails to properly sanitize input parameters before executing system calls. This lack of input validation creates a command injection vector that allows arbitrary OS command execution with root privileges. The vulnerability stems from improper input handling and insufficient sanitization of user-supplied data within the device's configuration management utilities. According to CWE-77, this maps directly to command injection vulnerabilities where untrusted data is incorporated into system commands without proper validation or escaping mechanisms.
The operational impact of this vulnerability is severe and far-reaching for organizations still relying on these deprecated devices. An attacker with network access and valid credentials can escalate privileges to root level and execute any command available on the system. This includes but is not limited to creating new user accounts, modifying firewall rules, accessing network traffic, establishing backdoors, or even wiping device configurations. The implications extend beyond simple privilege escalation as the attacker gains complete control over the network perimeter device, potentially allowing them to monitor, redirect, or disrupt network communications. This vulnerability directly aligns with ATT&CK technique T1059.001 for command and scripting interpreter, where adversaries use legitimate system tools to execute commands and gain access to the underlying system.
Organizations should immediately implement multiple layers of mitigation strategies to address this vulnerability. The most critical immediate action involves disabling Telnet services entirely on affected devices and migrating to SSH-based management interfaces where available. Network segmentation should be implemented to isolate these devices from critical network segments, and access controls should be strictly enforced through firewall rules. Regular network monitoring should be enhanced to detect unusual command execution patterns or unauthorized Telnet connections. Additionally, organizations must conduct comprehensive inventory audits to identify all remaining legacy devices and develop a timeline for their complete retirement from production environments. The vulnerability highlights the importance of maintaining up-to-date firmware and avoiding the use of end-of-life products that no longer receive security patches or support from vendors.