CVE-2018-0639 in HC100RC
Summary
by MITRE
Aterm HC100RC Ver1.0.1 and earlier allows attacker with administrator rights to execute arbitrary OS commands via tools_firmware.cgi date parameter, time parameter, and offset parameter.
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Analysis
by VulDB Data Team • 04/27/2020
The vulnerability identified as CVE-2018-0639 affects Aterm HC100RC devices running firmware version 1.0.1 and earlier, representing a critical command injection flaw that enables authenticated attackers with administrative privileges to execute arbitrary operating system commands. This vulnerability resides within the tools_firmware.cgi web interface component that handles firmware-related operations, specifically targeting three parameters: date, time, and offset. The flaw demonstrates characteristics consistent with CWE-77 command injection, where untrusted input is directly incorporated into operating system command execution without proper sanitization or validation.
The technical implementation of this vulnerability occurs through the improper handling of user-supplied parameters within the firmware management interface. When administrators interact with the tools_firmware.cgi script, the date, time, and offset parameters are concatenated directly into system commands without adequate input validation or sanitization mechanisms. This allows an attacker with administrative access to manipulate these parameters in ways that result in arbitrary command execution on the underlying operating system. The vulnerability essentially creates a path where user-controllable input flows directly into shell execution contexts, bypassing normal security controls and authorization checks.
From an operational impact perspective, this vulnerability represents a severe threat to network security and device integrity. An attacker who has already gained administrative credentials can leverage this flaw to escalate their privileges further, potentially gaining root access to the device's operating system. The implications extend beyond simple command execution as the attacker could modify firmware, install malicious software, alter system configurations, or establish persistent backdoors. The vulnerability undermines the fundamental security assumptions of the device, as it allows authenticated users to bypass the intended security boundaries of the firmware management interface.
The attack vector for this vulnerability requires an attacker to already possess administrative credentials, making it a privilege escalation issue rather than a direct remote code execution vulnerability. However, the impact remains significant as it provides a pathway for attackers who have already compromised administrative accounts to gain more extensive control over the device. This vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation, as it enables attackers to execute system commands and potentially elevate their access level. The vulnerability also demonstrates weaknesses in input validation and secure coding practices that should be addressed through proper parameter sanitization and the principle of least privilege in web application development.
Mitigation strategies for CVE-2018-0639 should focus on immediate firmware updates from the vendor to address the command injection vulnerability. Organizations should also implement network segmentation to limit access to administrative interfaces, enforce strong authentication controls, and conduct regular security assessments of network devices. Additional measures include monitoring for unusual command execution patterns, implementing web application firewalls to detect malicious parameter manipulation, and ensuring that administrative access is restricted to authorized personnel only. The vulnerability underscores the importance of regular security updates and the need for robust input validation in all web applications, particularly those handling sensitive system operations.