CVE-2026-3587 in Lean Managed Switch 852-1812
Summary
by MITRE • 03/23/2026
An unauthenticated remote attacker can exploit a hidden function in the CLI prompt to escape the restricted interface, leading to full compromise of the device.
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Analysis
by VulDB Data Team • 03/27/2026
This vulnerability represents a critical security flaw in network device command line interfaces that allows unauthenticated remote attackers to bypass authentication mechanisms and access unrestricted system functionality. The issue stems from a hidden or undocumented function within the command line interface that provides unintended escape routes from the restricted user environment. Such hidden functions often arise from incomplete security testing or legacy code that was never properly secured during development cycles. The vulnerability enables attackers to transition from a restricted user context to full administrative privileges without requiring valid credentials, effectively providing a backdoor access mechanism that undermines the fundamental security model of the device.
The technical implementation of this flaw involves a specific command or sequence of commands that exists within the CLI but is not properly documented or secured. This hidden functionality likely operates through command injection patterns or privilege escalation mechanisms that were intended for legitimate administrative purposes but were not adequately protected from unauthorized access. The vulnerability can be exploited remotely without authentication, meaning that an attacker can access the device over the network and execute the escape sequence from any location. This type of vulnerability typically falls under CWE-284 which addresses improper access control, and may also relate to CWE-78 which covers OS command injection, depending on the exact implementation details. The attack vector demonstrates characteristics of techniques found in the MITRE ATT&CK framework under T1078 for valid accounts and T1059 for command and scripting interpreter, as it enables execution of arbitrary commands through the command line interface.
The operational impact of this vulnerability is severe as it provides complete compromise of the affected device, potentially allowing attackers to gain full administrative control over network infrastructure. Once exploited, the attacker can modify device configurations, install malicious software, monitor network traffic, or use the compromised device as a pivot point for attacking other systems within the network. The vulnerability affects network devices such as routers, switches, firewalls, and other infrastructure equipment where CLI access is available. The remote exploitation capability means that attackers do not need physical access or network proximity, making the vulnerability particularly dangerous for enterprise networks. Organizations may face significant operational disruption, data breaches, and potential regulatory compliance violations if these devices are compromised, as the vulnerability essentially removes the authentication layer that protects critical network infrastructure.
Mitigation strategies should focus on immediate remediation through firmware updates from vendors that properly secure or remove the hidden functionality. Network administrators should conduct comprehensive audits of all CLI interfaces to identify similar hidden functions or undocumented features that could present similar risks. Access controls should be strengthened through proper configuration of authentication mechanisms, ensuring that all command line interfaces are properly secured and that only authorized personnel can access administrative functions. Network segmentation and monitoring should be implemented to detect unusual command execution patterns that might indicate exploitation attempts. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other network infrastructure components. The vulnerability highlights the importance of proper input validation and access control implementation in network device software, and organizations should ensure that all code undergoes thorough security testing including threat modeling and secure coding practices to prevent similar issues in the future.