CVE-2025-4445: D-Link DIR-605L RCE Vulnerability

CVE-2025-4445 Overview

A critical command injection vulnerability has been identified in D-Link DIR-605L firmware version 2.13B01. The vulnerability exists in the wake_on_lan function where improper handling of the mac argument allows remote attackers to inject and execute arbitrary commands on the affected device. This vulnerability affects an end-of-life product that is no longer supported by D-Link, making it particularly dangerous for organizations still running this hardware.

Critical Impact

Remote attackers can exploit the command injection in the wake_on_lan function to execute arbitrary system commands on vulnerable D-Link DIR-605L routers, potentially leading to complete device compromise and network infiltration.

Affected Products

• D-Link DIR-605L Firmware version 2.13B01
• D-Link DIR-605L Hardware (all revisions running vulnerable firmware)

Discovery Timeline

• 2025-05-09 - CVE-2025-4445 published to NVD
• 2025-05-13 - Last updated in NVD database

Technical Details for CVE-2025-4445

Vulnerability Analysis

This command injection vulnerability stems from insufficient input validation in the wake_on_lan function of the D-Link DIR-605L router firmware. The affected function processes the mac parameter without proper sanitization, allowing an attacker to embed shell metacharacters and inject malicious commands that execute with the privileges of the web server process on the device.

Command injection vulnerabilities in network devices are particularly severe because they typically run with elevated privileges and provide direct access to network infrastructure. In the case of the DIR-605L, successful exploitation could allow an attacker to intercept network traffic, modify device configuration, establish persistent backdoors, or pivot to other systems on the network.

The vulnerability is especially concerning as the D-Link DIR-605L has reached end-of-life status and will not receive security patches from the vendor, leaving affected devices permanently vulnerable.

Root Cause

The root cause is an instance of CWE-77 (Command Injection) and CWE-74 (Improper Neutralization of Special Elements in Output). The wake_on_lan function fails to properly sanitize user-supplied input in the mac parameter before passing it to system shell commands. This allows special characters such as semicolons, pipes, or backticks to break out of the intended command context and execute attacker-controlled commands.

Attack Vector

The attack can be launched remotely over the network. An authenticated attacker with access to the router's administrative interface can manipulate the mac argument in requests to the wake_on_lan function. By injecting shell metacharacters followed by malicious commands, the attacker can achieve arbitrary command execution on the underlying operating system. The network-based attack vector combined with low attack complexity makes this vulnerability accessible to a wide range of threat actors.

For technical details on the exploitation mechanism, refer to the GitHub PoC documentation and the VulDB entry.

Detection Methods for CVE-2025-4445

Indicators of Compromise

• Unexpected outbound connections from the router to external IP addresses
• Modified router configuration or firmware settings without administrator action
• Anomalous process execution on the device (if logging is available)
• Unusual entries in router access logs related to the wake_on_lan function
• Network traffic patterns indicating command and control communication

Detection Strategies

• Monitor HTTP/HTTPS requests to router administration interfaces for suspicious mac parameter values containing shell metacharacters (;, |, &, backticks)
• Implement network-based intrusion detection rules to identify command injection payloads targeting D-Link device endpoints
• Review router access logs for repeated authentication attempts or unusual administrative function calls
• Deploy network segmentation monitoring to detect unauthorized lateral movement originating from network devices

Monitoring Recommendations

• Implement continuous network traffic analysis for D-Link DIR-605L devices
• Enable and centralize logging for all administrative interface access attempts
• Monitor for firmware modifications or unexpected configuration changes
• Deploy SentinelOne Singularity to detect malicious activity originating from compromised network infrastructure targeting endpoints

How to Mitigate CVE-2025-4445

Immediate Actions Required

• Immediately replace D-Link DIR-605L routers with currently supported hardware from D-Link or alternative vendors
• Isolate affected devices from critical network segments until replacement is completed
• Disable remote administration access to affected routers
• Implement strict network access controls limiting who can reach the router's administrative interface
• Review network logs for evidence of prior exploitation attempts

Patch Information

No patch is available for this vulnerability. D-Link has confirmed that the DIR-605L has reached end-of-life status and will not receive security updates. The vendor was contacted early about this disclosure but cannot provide remediation for unsupported products. Organizations must replace affected hardware with supported alternatives to address this vulnerability. Refer to the D-Link official website for information on current product offerings.

Workarounds

• Replace the end-of-life DIR-605L with a currently supported router model
• Disable Wake-on-LAN functionality if possible through router configuration
• Implement firewall rules to block external access to the router's administrative interface
• Place affected routers behind a VPN or additional access control layer
• Consider deploying third-party firmware such as DD-WRT or OpenWrt if compatible, though this carries its own risks

# Example: Restrict administrative access via firewall (implement on upstream firewall)
# Block external access to router management interface
iptables -A FORWARD -d <ROUTER_IP> -p tcp --dport 80 -j DROP
iptables -A FORWARD -d <ROUTER_IP> -p tcp --dport 443 -j DROP

# Allow only specific management network
iptables -I FORWARD -s <MANAGEMENT_SUBNET> -d <ROUTER_IP> -p tcp --dport 80 -j ACCEPT