CVE-2018-5704 in Open On-Chip Debugger
Summary
by MITRE
Open On-Chip Debugger (OpenOCD) 0.10.0 does not block attempts to use HTTP POST for sending data to 127.0.0.1 port 4444, which allows remote attackers to conduct cross-protocol scripting attacks, and consequently execute arbitrary commands, via a crafted web site.
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Analysis
by VulDB Data Team • 01/20/2023
The Open On-Chip Debugger vulnerability CVE-2018-5704 represents a critical security flaw in the 0.10.0 version of this widely used debugging tool for embedded systems. This vulnerability stems from the improper handling of HTTP POST requests directed toward the local port 4444, which serves as the default communication endpoint for OpenOCD's built-in HTTP server. The flaw enables remote attackers to exploit cross-protocol scripting attacks by crafting malicious websites that can interact with the vulnerable OpenOCD instance running on target systems. This issue directly violates security principles by allowing unauthorized remote code execution through a seemingly benign web-based attack vector that leverages the HTTP protocol to communicate with a service bound to localhost.
The technical implementation of this vulnerability involves the failure of OpenOCD to properly validate or restrict incoming HTTP requests on its local port 4444. When an attacker crafts a malicious website containing specially designed HTTP POST requests, these requests can be executed through a victim's browser against the OpenOCD instance listening on 127.0.0.1:4444. This creates a dangerous attack surface where the HTTP server component does not adequately separate the local debugging interface from potential remote exploitation. The vulnerability specifically affects the protocol handling mechanism within OpenOCD's HTTP server implementation, allowing attackers to bypass normal access controls and potentially execute arbitrary commands on the system. This flaw is categorized under CWE-284 Access Control Issues, as it represents a failure in properly restricting access to privileged resources.
The operational impact of CVE-2018-5704 is particularly severe for embedded system developers and security professionals who rely on OpenOCD for debugging and programming microcontrollers. Attackers can leverage this vulnerability to gain unauthorized access to development environments, potentially compromising the integrity of embedded firmware updates, accessing sensitive debugging information, or executing malicious code on target devices. The cross-protocol scripting nature of the attack means that even systems with proper network segmentation may be vulnerable if users browse malicious websites while OpenOCD is running locally. This vulnerability affects the broader embedded security ecosystem, as many development workflows involve running OpenOCD in environments where users may encounter untrusted web content, creating an attack vector that can compromise entire development pipelines and potentially lead to supply chain attacks.
The mitigation strategies for this vulnerability primarily involve upgrading to a patched version of OpenOCD that properly restricts HTTP POST requests to localhost interfaces. Security practitioners should implement network segmentation to prevent direct access to port 4444 from external networks, while also ensuring that OpenOCD is only run in secure development environments where the risk of malicious web content is minimized. Additional protective measures include disabling the HTTP server component when not actively needed, restricting the listening interface to specific network interfaces rather than all interfaces, and implementing proper access controls that limit who can interact with the debugging infrastructure. Organizations should also consider implementing network monitoring to detect unusual HTTP traffic patterns that may indicate exploitation attempts, and apply the principle of least privilege when configuring OpenOCD instances to reduce potential attack surface. This vulnerability demonstrates the importance of secure coding practices in network services and highlights the need for proper input validation and access control mechanisms in debugging tools that are commonly exposed to potentially untrusted environments.