CVE-2018-14529 in NVX220
Summary
by MITRE
Invoxia NVX220 devices allow access to /bin/sh via escape from a restricted CLI, leading to disclosure of password hashes.
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Analysis
by VulDB Data Team • 10/17/2023
The vulnerability identified as CVE-2018-14529 affects Invoxia NVX220 devices and represents a critical privilege escalation flaw that enables unauthorized access to system shells through a command injection vulnerability in the device's restricted command line interface. This vulnerability stems from inadequate input validation and sanitization within the device's CLI implementation, allowing malicious actors to escape the intended restricted environment and gain access to the underlying operating system shell. The flaw specifically targets the device's authentication mechanism by enabling attackers to extract password hashes directly from the system, potentially compromising the entire network infrastructure.
The technical exploitation of this vulnerability follows a classic command injection pattern where the restricted CLI fails to properly validate user inputs before executing system commands. Attackers can leverage this weakness to bypass the intended security boundaries of the CLI environment and execute arbitrary shell commands with elevated privileges. The vulnerability is particularly concerning because it provides direct access to the system shell without requiring authentication, and the extracted password hashes can subsequently be subjected to offline brute force attacks or credential reuse attacks against other network services. This type of vulnerability aligns with CWE-78, which describes improper neutralization of special elements used in OS commands, and represents a clear violation of the principle of least privilege in system design.
The operational impact of CVE-2018-14529 extends beyond simple credential theft, as it provides attackers with persistent access to the device's underlying operating system and potentially enables further lateral movement within the network. Once an attacker gains shell access through this vulnerability, they can modify system configurations, install malicious software, or establish backdoors for continued access. The exposure of password hashes creates additional attack vectors for credential-based attacks, particularly if weak passwords are used or if the hashes are successfully cracked through rainbow table attacks or brute force methods. This vulnerability represents a significant risk to network security posture and can result in complete device compromise, data exfiltration, and potential disruption of critical communication services.
Organizations should implement immediate mitigations including firmware updates from Invoxia to address the CLI escape vulnerability, network segmentation to limit access to these devices, and enhanced monitoring for suspicious CLI usage patterns. Security controls should focus on implementing proper input validation mechanisms, restricting shell access to authorized personnel only, and deploying intrusion detection systems to monitor for exploitation attempts. The vulnerability also highlights the importance of secure coding practices and regular security assessments of network infrastructure devices, particularly those with web-based or CLI interfaces that may be subject to command injection attacks. According to ATT&CK framework, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: Shell Script) and T1003.001 (Credential Access: T1003.001), emphasizing both the execution and credential access aspects of the threat. Device administrators should also consider implementing multi-factor authentication mechanisms and regular security audits to prevent unauthorized access to critical network infrastructure components.