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

CVE-2026-1506 Overview

CVE-2026-1506 is an operating system command injection vulnerability in the D-Link DIR-615 wireless router running firmware version 4.10. The flaw resides in the MAC Filter Configuration component, specifically in the /adv_mac_filter.php script. An authenticated remote attacker can manipulate the mac argument to inject arbitrary operating system commands. The exploit technique has been publicly disclosed. D-Link no longer supports the DIR-615 4.10 hardware revision, so no vendor patch will be issued. The weakness is tracked under [CWE-77] and [CWE-78].

Critical Impact
Authenticated attackers can execute arbitrary OS commands on the router with device privileges, leading to full device compromise, traffic interception, and lateral movement into the connected network.

Affected Products

D-Link DIR-615 router (hardware revision D)
D-Link DIR-615 firmware version 4.10
End-of-life D-Link DIR-615 deployments still in production use

Discovery Timeline

2026-01-28 - CVE-2026-1506 published to NVD
2026-01-30 - Last updated in NVD database

Technical Details for CVE-2026-1506

Vulnerability Analysis

The DIR-615 web administration interface exposes a MAC filtering page implemented in /adv_mac_filter.php. The page accepts a mac parameter that is intended to hold a hardware address used for filter rules. The script passes this parameter into a downstream shell command without proper sanitization or argument quoting. Attackers can append shell metacharacters to the mac value to break out of the intended command and execute additional commands within the router's BusyBox shell. Because the router runs core services as a privileged user, injected commands inherit broad access to the file system, network interfaces, and configuration store.

Root Cause

The defect is a classic failure to neutralize special elements used in an OS command, mapped to [CWE-78]. The PHP handler invokes a system call to apply MAC filter rules and concatenates the attacker-controlled mac value into the command string. No input validation enforces the expected XX:XX:XX:XX:XX:XX format, and no escaping or parameterized invocation is performed before the shell evaluates the string.

Attack Vector

Exploitation requires network reachability to the router's administrative interface and valid high-privilege credentials. The attacker submits a crafted HTTP POST request to /adv_mac_filter.php with a mac value containing shell metacharacters such as backticks, semicolons, or $(...) constructs. The injected payload executes during MAC filter rule processing. Successful exploitation yields command execution as the web service account, which on DIR-615 firmware is effectively root. See the Notion Security Document and VulDB #343118 for technical details on the request structure.

Detection Methods for CVE-2026-1506

Indicators of Compromise

HTTP POST requests to /adv_mac_filter.php containing shell metacharacters (;, |, &, backticks, $()) in the mac parameter
MAC filter configuration entries that deviate from the canonical XX:XX:XX:XX:XX:XX hexadecimal format
Unexpected outbound connections from the router's WAN interface to unfamiliar hosts shortly after administrative sessions
New or modified processes spawned by the router's web management daemon

Detection Strategies

Inspect web server access logs on the DIR-615 for requests to /adv_mac_filter.php and flag any mac parameter that fails strict MAC address regex validation
Deploy network IDS signatures that match command injection patterns inside HTTP request bodies destined for the router management VLAN
Correlate administrative login events with subsequent configuration changes to detect abuse of authenticated sessions

Monitoring Recommendations

Restrict and monitor access to the router management interface using a dedicated management VLAN with explicit allowlists
Capture and review router syslog output for anomalous shell activity or process executions originating from the HTTP daemon
Track DNS queries and egress traffic from the router itself, not just clients behind it, to identify command-and-control behavior

How to Mitigate CVE-2026-1506

Immediate Actions Required

Disable remote management on the WAN interface and limit LAN-side administrative access to a small set of trusted hosts
Rotate the router administrator password and remove any unused administrative accounts to reduce the authenticated attack surface
Replace end-of-life DIR-615 4.10 devices with a currently supported router model that receives security updates

Patch Information

No patch is available. D-Link has confirmed that the DIR-615 4.10 hardware revision is end-of-life and outside its support window. Refer to the D-Link Official Website for end-of-life product notices and replacement guidance.

Workarounds

Place the router behind an upstream firewall and block external access to TCP ports used by the administrative web interface
Avoid using the MAC Filter feature on affected firmware to reduce exposure of the vulnerable code path
Segment the router from sensitive internal networks so that a compromised device cannot reach critical assets

bash

# Example: restrict management plane access using upstream firewall rules
# Allow only a designated admin host to reach the router management interface
iptables -A FORWARD -s 192.0.2.10 -d 192.168.0.1 -p tcp --dport 80 -j ACCEPT
iptables -A FORWARD -d 192.168.0.1 -p tcp --dport 80 -j DROP
iptables -A FORWARD -d 192.168.0.1 -p tcp --dport 443 -j DROP