CVE-2018-25143 in IPn4G
Summary
by MITRE • 12/24/2025
Microhard Systems IPn4G 1.1.0 contains a service vulnerability that allows authenticated users to enable a restricted SSH shell with a default 'msshc' user. Attackers can exploit a custom 'ping' command in the NcFTP environment to escape the restricted shell and execute commands with root privileges.
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Analysis
by VulDB Data Team • 12/25/2025
The vulnerability identified as CVE-2018-25143 affects Microhard Systems IPn4G version 1.1.0, representing a critical service-level flaw that undermines the security posture of network infrastructure devices. This issue stems from improper privilege management within the device's SSH service implementation, creating an exploitable pathway for authenticated attackers to escalate their privileges from standard user level to root access. The vulnerability specifically targets the restricted shell environment that is intended to limit user capabilities while maintaining system security. The default 'msshc' user account provides an initial foothold for exploitation, demonstrating poor security configuration practices that leave devices susceptible to privilege escalation attacks.
The technical exploitation mechanism leverages a custom 'ping' command embedded within the NcFTP environment, which serves as an unexpected backdoor for command execution. This flaw represents a classic case of insecure command execution within restricted environments, where the custom ping implementation fails to properly sanitize or validate input parameters. The NcFTP environment's integration with the restricted shell creates a dangerous intersection where legitimate administrative functionality becomes a vector for privilege escalation. The vulnerability operates through command injection techniques that bypass the intended restrictions of the shell, allowing attackers to execute arbitrary system commands with elevated privileges. This type of vulnerability aligns with CWE-78, which addresses improper neutralization of special elements used in OS commands, and CWE-20, covering input validation issues that can lead to command injection attacks.
From an operational impact perspective, this vulnerability compromises the integrity and confidentiality of network infrastructure devices running the affected Microhard Systems IPn4G firmware. Successful exploitation enables attackers to gain full administrative control over the device, potentially leading to network disruption, data exfiltration, or use as a pivot point for further attacks within the network. The restricted shell environment that was designed to prevent unauthorized access becomes ineffective due to the command injection flaw, undermining the principle of least privilege that should govern all system access controls. Organizations relying on this equipment face significant risk of unauthorized network access and potential compromise of their entire network infrastructure, particularly in environments where such devices are used for critical communications.
Mitigation strategies for CVE-2018-25143 should prioritize immediate firmware updates from Microhard Systems to address the underlying privilege escalation vulnerability. Network administrators must disable unnecessary services and accounts, particularly the default 'msshc' user, while implementing strict access controls and monitoring for suspicious SSH activity. The implementation of network segmentation and firewall rules can limit the attack surface and prevent lateral movement once exploitation occurs. Regular security assessments should include verification of shell environments and command execution mechanisms to ensure no similar vulnerabilities exist in other system components. Additionally, organizations should consider implementing intrusion detection systems that can identify anomalous command execution patterns and unauthorized privilege escalation attempts. This vulnerability demonstrates the importance of proper privilege separation and input validation in restricted environments, aligning with ATT&CK technique T1068 which covers exploit for privilege escalation and T1566 which addresses credential harvesting through various attack vectors.