CVE-2018-18879 in MicroServer
Summary
by MITRE
In firmware version MS_2.6.9900 of Columbia Weather MicroServer, an authenticated web user can pipe commands directly to the underlying operating system as user input is not sanitized in networkdiags.php.
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Analysis
by VulDB Data Team • 10/06/2023
The vulnerability identified as CVE-2018-18879 affects the Columbia Weather MicroServer firmware version MS_2.6.9900, presenting a critical command injection flaw that stems from inadequate input validation within the networkdiags.php web interface component. This security weakness allows authenticated users to execute arbitrary system commands by manipulating input parameters that are directly passed to the underlying operating system without proper sanitization. The flaw exists within the network diagnostics functionality where user-provided data is processed and subsequently executed as shell commands, creating a pathway for malicious exploitation.
The technical implementation of this vulnerability aligns with CWE-77, which categorizes command injection flaws where untrusted data is incorporated into command execution contexts. Attackers can leverage this vulnerability by crafting malicious input through the web interface to the networkdiags.php script, which then forwards these inputs directly to system shell commands. This creates a persistent threat vector where authenticated users with legitimate access can escalate their privileges and execute arbitrary code with the privileges of the web server process, typically running as a system user with elevated permissions.
The operational impact of this vulnerability extends beyond simple command execution, as it provides attackers with a potential foothold for further system compromise. An attacker who gains access to the web interface can potentially escalate privileges to root or system-level access, depending on how the web server is configured and what privileges the underlying process operates under. The vulnerability affects the integrity and confidentiality of the weather monitoring system, as attackers can extract sensitive data, modify system configurations, or even establish persistent backdoors. Additionally, the attack surface is expanded since the vulnerability requires only authenticated access, making it more accessible than some other remote code execution flaws that require additional reconnaissance or exploitation steps.
Mitigation strategies for CVE-2018-18879 should focus on immediate input validation and sanitization measures within the networkdiags.php script. The firmware should implement proper parameter validation and sanitization to prevent user input from being executed as shell commands. This includes implementing proper input filtering, using secure coding practices that avoid direct shell command execution, and implementing proper access controls that limit command execution capabilities. Organizations should also consider implementing network segmentation to limit access to the affected system, deploying web application firewalls to detect and block malicious payloads, and ensuring that firmware updates are applied promptly. The vulnerability demonstrates the importance of following secure coding practices and adhering to the principle of least privilege in system design. From an ATT&CK framework perspective, this vulnerability maps to T1059.001 for command and script injection, and potentially T1068 for exploit for privilege escalation, emphasizing the need for robust input validation and secure coding practices across all web application components.