CVE-2026-2151: D-Link DIR-615 Firmware RCE Vulnerability

CVE-2026-2151 Overview

CVE-2026-2151 is an OS command injection vulnerability in the D-Link DIR-615 4.10 router. The flaw resides in the adv_firewall.php file within the DMZ Host Feature component. Attackers can manipulate the dmz_ipaddr argument to inject and execute arbitrary operating system commands. The vulnerability is remotely exploitable and has been publicly disclosed. D-Link no longer supports the DIR-615 4.10 hardware, meaning no official patch will be issued. The flaw is tracked under [CWE-77] Command Injection and [CWE-78] OS Command Injection.

Critical Impact
Remote attackers with authenticated access can execute arbitrary OS commands on the router, leading to complete device compromise and pivoting into the internal network.

Affected Products

D-Link DIR-615 router hardware (end-of-life)
D-Link DIR-615 Firmware version 4.10
Any deployment exposing the adv_firewall.php administrative interface

Discovery Timeline

2026-02-08 - CVE-2026-2151 published to NVD
2026-02-11 - Last updated in NVD database

Technical Details for CVE-2026-2151

Vulnerability Analysis

The DIR-615 web administration interface exposes the DMZ Host configuration through adv_firewall.php. The script accepts a dmz_ipaddr parameter intended to hold an IPv4 address for the DMZ host. The firmware fails to sanitize or validate this parameter before passing it to an underlying shell command. Attackers can append shell metacharacters such as ;, |, or backticks to inject arbitrary commands. The injected commands execute with the privileges of the web server process, which typically runs as root on consumer routers. This grants full control over the device, including credential theft, firmware modification, traffic interception, and lateral movement into the LAN.

Root Cause

The root cause is improper neutralization of special elements used in an OS command. The dmz_ipaddr argument is concatenated directly into a system call without input validation or argument escaping. There is no allowlist enforcement to restrict the value to a valid IPv4 dotted-quad format.

Attack Vector

Exploitation requires network access to the router's management interface and high-privilege credentials, per the CVSS vector. An attacker submits a crafted HTTP request to adv_firewall.php with a malicious dmz_ipaddr payload. The router executes the appended command during DMZ configuration processing. Public disclosure of the exploit details on third-party platforms increases the likelihood of opportunistic attacks against exposed devices.

No verified public exploit code is reproduced here. Technical details are available in the DIR-615 OS Command Injection write-up and VulDB entry #344853.

Detection Methods for CVE-2026-2151

Indicators of Compromise

HTTP POST or GET requests to /adv_firewall.php containing shell metacharacters (;, |, &, backticks, $()) in the dmz_ipaddr parameter
Unexpected outbound connections from the router to attacker-controlled infrastructure
New or unknown processes running on the router, including reverse shells or download utilities such as wget or tftp
Modifications to router configuration files or unexpected firmware integrity changes

Detection Strategies

Inspect web server access logs on the device for non-IPv4 strings submitted to dmz_ipaddr
Deploy network IDS rules to flag HTTP requests targeting adv_firewall.php with payloads containing command separators
Monitor DNS and NetFlow telemetry for anomalous traffic originating from router management interfaces

Monitoring Recommendations

Forward router syslog and management plane traffic to a centralized SIEM for correlation
Baseline normal administrative activity to surface unauthorized access to adv_firewall.php
Alert on outbound connections from network infrastructure devices to non-corporate destinations

How to Mitigate CVE-2026-2151

Immediate Actions Required

Decommission and replace the DIR-615 4.10, as the device is end-of-life and will not receive a vendor patch
Disable remote administration on the WAN interface to limit exposure to internet-based attackers
Restrict LAN-side access to the management interface using ACLs or a dedicated management VLAN
Rotate all credentials stored on or behind the affected router, including Wi-Fi pre-shared keys

Patch Information

No patch is available. D-Link confirms the DIR-615 4.10 is outside the supported product lifecycle. Refer to D-Link Security Resources for end-of-life guidance and recommended replacement models.

Workarounds

Place the router behind an upstream firewall and block inbound access to TCP/80 and TCP/443 on the WAN interface
Disable the DMZ Host feature entirely if not required for operations
Enforce strong, unique administrator credentials and remove default accounts to raise the bar for the authenticated attack precondition

bash

# Example: block external access to the router management interface using upstream iptables
iptables -A FORWARD -p tcp -d <router_lan_ip> --dport 80 -j DROP
iptables -A FORWARD -p tcp -d <router_lan_ip> --dport 443 -j DROP