CVE-2018-21117 in XR500
Summary
by MITRE
NETGEAR XR500 devices before 2.3.2.32 are affected by remote code execution by unauthenticated attackers via the traceroute handler.
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Analysis
by VulDB Data Team • 06/01/2024
The vulnerability identified as CVE-2018-21117 affects NETGEAR XR500 wireless routers and is classified as a remote code execution flaw that can be exploited by unauthenticated attackers. This critical vulnerability resides within the traceroute handler component of the device firmware, which is accessible without requiring any authentication credentials. The affected devices are specifically those running firmware versions prior to 2.3.2.32, making a significant portion of deployed XR500 devices susceptible to exploitation. The vulnerability represents a serious security weakness that allows attackers to execute arbitrary code on the affected devices from remote locations, potentially leading to complete system compromise.
The technical flaw in CVE-2018-21117 stems from improper input validation within the traceroute handler functionality. When the device processes incoming traceroute requests, it fails to properly sanitize user-supplied input parameters, creating a classic buffer overflow or command injection vulnerability. This allows an attacker to craft malicious input that gets executed within the context of the device's operating system. The vulnerability is particularly dangerous because it operates at the network level, where the traceroute handler is exposed to external traffic without authentication requirements. The flaw essentially provides attackers with a backdoor into the device's command execution environment, enabling them to run arbitrary commands with the privileges of the device's system user.
The operational impact of this vulnerability is severe and multifaceted for affected organizations and end users. An unauthenticated attacker can gain complete control over the affected NETGEAR XR500 devices, potentially leading to unauthorized network access, data exfiltration, or the device being used as a pivot point for further attacks within the network. The vulnerability allows for persistent access to the device, enabling attackers to install malware, modify network configurations, or establish command and control channels. Organizations relying on these devices for network infrastructure may experience service disruption, security breaches, or compliance violations if the vulnerability is exploited. The remote nature of the attack means that attackers can exploit the vulnerability from anywhere on the internet, making it particularly challenging to defend against.
Mitigation strategies for CVE-2018-21117 should focus on immediate firmware updates to version 2.3.2.32 or later, which contain the necessary patches to address the vulnerability. Network administrators should also implement network segmentation to limit exposure of affected devices to external traffic, particularly by blocking access to the traceroute handler port or service. Additional protective measures include deploying network monitoring solutions to detect anomalous traceroute traffic patterns and implementing intrusion detection systems that can identify exploitation attempts. Organizations should also consider disabling the traceroute functionality entirely if it is not required for network operations. This vulnerability aligns with CWE-78 and CWE-121 categories related to command injection and buffer overflow, and maps to ATT&CK techniques such as T1059 for command and scripting interpreter and T1071 for application layer protocol. Regular vulnerability assessments and network hygiene practices should be maintained to prevent similar issues in the future, including proper input validation and secure coding practices during device development.