CVE-2016-6534 in NMIS
Summary
by MITRE
Opmantek NMIS before 4.3.7c has command injection via man, finger, ping, trace, and nslookup in the tools.pl CGI script. Versions before 8.5.12G might be affected in non-default configurations.
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Analysis
by VulDB Data Team • 08/28/2020
The vulnerability identified as CVE-2016-6534 affects Opmantek NMIS versions prior to 4.3.7c and potentially versions before 8.5.12G in non-default configurations. This represents a critical command injection flaw that resides within the tools.pl CGI script, which serves as a gateway for various network diagnostic utilities. The affected functionality includes man, finger, ping, trace, and nslookup commands that are executed through the web interface, creating an exploitable attack surface where malicious input can be interpreted and executed as system commands.
The technical flaw stems from insufficient input validation and sanitization within the tools.pl script, allowing attackers to inject arbitrary commands through parameters that are passed directly to system shell functions. When users interact with the network diagnostic tools through the web interface, the application fails to properly escape or filter user-supplied input before executing system calls. This design weakness enables an attacker to append malicious commands to legitimate utility parameters, effectively bypassing normal access controls and executing unauthorized operations on the underlying operating system. The vulnerability aligns with CWE-77 and CWE-94 categories, which specifically address command injection and code injection flaws in software applications.
The operational impact of this vulnerability is severe and multifaceted, as it provides attackers with potential full system compromise capabilities. An attacker who successfully exploits this vulnerability can execute arbitrary commands with the privileges of the web server process, which typically runs with elevated permissions. This could lead to complete system takeover, data exfiltration, privilege escalation to root or administrator accounts, and the establishment of persistent backdoors. The attack surface extends beyond simple command execution to include potential lateral movement within the network, as the compromised system may serve as a launching point for further attacks against other networked systems. According to ATT&CK framework, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: PowerShell) and T1068 (Exploitation for Privilege Escalation) techniques.
Mitigation strategies for CVE-2016-6534 should prioritize immediate patch application to versions 4.3.7c or later, which contain proper input validation and sanitization measures. Organizations should also implement network segmentation to limit access to the affected web interface, restrict the web server's capabilities through privilege separation, and deploy web application firewalls to detect and block malicious input patterns. Additional protective measures include disabling unnecessary network diagnostic utilities when not actively required, implementing strict input validation at multiple layers of the application architecture, and conducting regular security assessments of web applications to identify similar vulnerabilities. System administrators should also monitor for suspicious command execution patterns and implement comprehensive logging to detect potential exploitation attempts. The remediation process must include thorough testing of patched versions to ensure that legitimate functionality remains intact while eliminating the command injection vulnerability.