CVE-2018-10967 in DIR-550A
Summary
by MITRE
On D-Link DIR-550A and DIR-604M devices through v2.10KR, a malicious user can forge an HTTP request to inject operating system commands that can be executed on the device with higher privileges, aka remote code execution.
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Analysis
by VulDB Data Team • 02/07/2020
The vulnerability identified as CVE-2018-10967 affects D-Link DIR-550A and DIR-604M wireless routers running firmware versions up to v2.10KR. This represents a critical remote code execution flaw that allows attackers to bypass authentication mechanisms and execute arbitrary operating system commands on the affected devices. The vulnerability stems from inadequate input validation within the web interface's handling of HTTP requests, creating a path for malicious actors to inject command sequences that are subsequently executed with elevated privileges. Such a flaw fundamentally compromises the device's security posture and provides attackers with unauthorized access to the underlying operating system.
The technical implementation of this vulnerability involves improper sanitization of user-supplied input within the router's web administration interface. When the device processes HTTP requests containing malicious command injection payloads, it fails to properly validate or escape special characters that could be interpreted as operating system commands. This weakness allows attackers to craft HTTP requests that include shell metacharacters such as semicolons, ampersands, or pipe operators, which are then executed by the device's command processor. The flaw is particularly dangerous because it operates at the operating system level, meaning successful exploitation grants attackers root-level privileges and complete control over the device's functionality.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass complete device compromise and potential network infiltration. Once an attacker achieves remote code execution, they can modify device configurations, install malicious software, create backdoors, or use the compromised router as a pivot point to attack other devices within the local network. The vulnerability affects devices that are commonly deployed in residential and small office environments, where network security measures may be insufficient, potentially leading to broader network compromise. This issue also violates fundamental security principles outlined in the OWASP Top Ten, particularly the category of injection flaws, and aligns with CWE-77 which describes command injection vulnerabilities.
From a threat modeling perspective, this vulnerability maps directly to the ATT&CK framework's technique T1059.001 for command and script interpretation, as well as T1078 for valid accounts and T1566 for malicious file execution. The attack surface is particularly concerning given that these routers are typically accessible from external networks without proper firewall rules, making them prime targets for automated scanning and exploitation. The vulnerability's impact is amplified by the fact that many users are unaware of their router's exposure to the internet, and default configurations often leave management interfaces accessible without strong authentication mechanisms. Organizations and individuals should immediately update to patched firmware versions, implement network segmentation, and ensure that router management interfaces are not exposed to untrusted networks to mitigate the risk of exploitation.
The vulnerability demonstrates the critical importance of proper input validation and secure coding practices in embedded systems. It highlights how seemingly simple flaws in HTTP request handling can lead to complete system compromise, emphasizing the need for defense-in-depth strategies that include network monitoring, regular firmware updates, and proper network architecture design. The affected devices represent a common class of consumer-grade networking equipment that often receives minimal security attention compared to enterprise solutions, making them attractive targets for attackers seeking to establish persistent access to networks.