CVE-2026-1506: D-Link DIR-615 RCE Vulnerability

CVE-2026-1506 Overview

A critical OS command injection vulnerability has been identified in the D-Link DIR-615 router firmware version 4.10. The vulnerability exists within the MAC Filter Configuration component, specifically in the /adv_mac_filter.php file. An attacker can exploit this flaw by manipulating the mac argument to inject arbitrary operating system commands, potentially leading to complete device compromise.

Critical Impact

Remote attackers with administrative access can execute arbitrary OS commands on the affected D-Link DIR-615 routers, potentially leading to complete device takeover, network pivoting, and data exfiltration. This product is no longer supported by D-Link, leaving affected devices permanently vulnerable.

Affected Products

• D-Link DIR-615 firmware version 4.10
• D-Link DIR-615 devices running affected MAC Filter Configuration component
• End-of-life D-Link DIR-615 router variants with /adv_mac_filter.php functionality

Discovery Timeline

• 2026-01-28 - CVE-2026-1506 published to NVD
• 2026-01-29 - Last updated in NVD database

Technical Details for CVE-2026-1506

Vulnerability Analysis

This vulnerability is classified as CWE-77 (Improper Neutralization of Special Elements used in a Command - Command Injection). The flaw exists in the MAC Filter Configuration functionality of the D-Link DIR-615 router's web management interface. The vulnerable component fails to properly sanitize user-supplied input in the mac parameter before incorporating it into system commands.

When an authenticated administrator configures MAC address filtering through the /adv_mac_filter.php endpoint, the mac argument value is passed directly to underlying OS commands without adequate input validation. This allows attackers with administrative credentials to append malicious shell commands that will be executed with the privileges of the router's web server process, typically running as root on embedded devices.

The attack requires network access to the device's management interface and administrative privileges, which limits the attack surface but does not eliminate the risk, particularly in environments with weak or default credentials.

Root Cause

The root cause of this vulnerability is insufficient input validation and sanitization in the MAC Filter Configuration handler. The /adv_mac_filter.php script accepts user input for the mac parameter and passes it directly to shell command execution functions without proper escaping or whitelisting of allowed characters. This allows shell metacharacters and command separators (such as ;, |, &&, or backticks) to break out of the intended command context and execute arbitrary commands.

Attack Vector

The attack vector is network-based, requiring an attacker to have access to the router's administrative interface and valid administrative credentials. The exploitation flow involves:

1. Authenticating to the D-Link DIR-615 web management interface
2. Navigating to the MAC Filter Configuration page (/adv_mac_filter.php)
3. Submitting a crafted request with malicious OS commands embedded in the mac parameter
4. The injected commands execute on the underlying Linux-based operating system

The vulnerability can be exploited remotely from any network segment that has access to the router's management interface. Additional technical details about the exploitation methodology are available in the Notion Security Guide.

Detection Methods for CVE-2026-1506

Indicators of Compromise

• Unexpected outbound connections from the router to unknown external IP addresses
• Modified configuration files or unauthorized firmware changes on D-Link DIR-615 devices
• Unusual process activity or new services running on the router
• Authentication logs showing access to /adv_mac_filter.php with suspicious mac parameter values containing shell metacharacters

Detection Strategies

• Monitor HTTP requests to /adv_mac_filter.php for unusual characters in the mac parameter (;, |, &&, $(), backticks)
• Implement network traffic analysis to detect command-and-control communications originating from router IP addresses
• Review web server access logs on managed network devices for patterns consistent with command injection attempts
• Deploy network-based intrusion detection rules to identify exploitation attempts targeting this vulnerability

Monitoring Recommendations

• Enable and regularly review authentication logs on D-Link DIR-615 devices
• Implement network segmentation to isolate router management interfaces from untrusted networks
• Monitor for firmware or configuration changes that may indicate successful exploitation
• Deploy SentinelOne Singularity™ for network visibility to detect anomalous device behavior and potential lateral movement from compromised routers

How to Mitigate CVE-2026-1506

Immediate Actions Required

• Replace affected D-Link DIR-615 devices with currently supported router models as this product has reached end-of-life status
• Restrict management interface access to trusted networks only using firewall rules or VLAN segmentation
• Change default administrative credentials and implement strong, unique passwords
• Disable remote management access if not required
• Monitor the device for signs of compromise while planning replacement

Patch Information

No patch is available for this vulnerability as the D-Link DIR-615 has reached end-of-life status and is no longer supported by the manufacturer. D-Link has discontinued security updates for this product line. Organizations should prioritize replacing affected devices with currently supported router models.

For additional context, refer to the VulDB entry #343118 and the D-Link Security Overview for information about supported products.

Workarounds

• Implement strict network access controls to limit management interface exposure to authorized administrator workstations only
• Deploy a network firewall or access control list (ACL) to block access to /adv_mac_filter.php from untrusted networks
• Consider placing the router behind an additional security appliance that can filter malicious requests
• Disable the MAC filtering feature if not operationally required to reduce attack surface

# Example: Restrict management access to specific IP on upstream firewall
iptables -A FORWARD -d <router_ip> -p tcp --dport 80 -s <admin_workstation_ip> -j ACCEPT
iptables -A FORWARD -d <router_ip> -p tcp --dport 80 -j DROP
iptables -A FORWARD -d <router_ip> -p tcp --dport 443 -s <admin_workstation_ip> -j ACCEPT
iptables -A FORWARD -d <router_ip> -p tcp --dport 443 -j DROP