CVE-2000-0152 in BorderManager
Summary
by MITRE
Remote attackers can cause a denial of service in Novell BorderManager 3.5 by pressing the enter key in a telnet connection to port 2000.
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Analysis
by VulDB Data Team • 01/03/2025
The vulnerability described in CVE-2000-0152 represents a classic denial of service weakness in Novell BorderManager 3.5 software that operates at the network protocol level. This flaw specifically manifests when remote attackers exploit the telnet service running on port 2000, which is a critical component of the BorderManager's administrative interface. The vulnerability stems from insufficient input validation and error handling within the telnet server implementation, creating a condition where malformed input can disrupt normal service operations. This type of vulnerability falls under the category of improper input handling as defined by CWE-20, which addresses weaknesses in the design or implementation of input validation mechanisms.
The technical exploitation of this vulnerability occurs through a simple yet effective method involving the transmission of an enter key press to the telnet service running on port 2000. When the BorderManager application receives this input without proper validation, it fails to process the command appropriately, leading to a service disruption that manifests as a denial of service condition. The flaw essentially creates a path where user input can cause the application to enter an undefined state, preventing legitimate administrative access and potentially rendering the BorderManager service unavailable to authorized users. This vulnerability demonstrates poor error handling practices and inadequate state management within the application's network service implementation.
The operational impact of CVE-2000-0152 extends beyond simple service disruption, as it can affect the overall security posture of organizations relying on Novell BorderManager for network security services. When an attacker can successfully execute a denial of service attack against the administrative interface, they effectively prevent authorized personnel from accessing critical security functions, potentially leaving the network vulnerable to other attacks. This vulnerability directly impacts the availability aspect of the CIA triad and can be categorized under the ATT&CK technique T1499.004 for network denial of service attacks. The simplicity of exploitation makes this vulnerability particularly dangerous as it requires minimal technical skill to execute, while potentially causing significant operational disruption.
Organizations utilizing Novell BorderManager 3.5 should implement immediate mitigations to address this vulnerability, including network segmentation to restrict access to port 2000, implementing firewall rules to limit telnet access, and applying vendor patches when available. The vulnerability highlights the importance of proper input validation and error handling in network services, which aligns with security best practices outlined in the OWASP Top Ten and NIST cybersecurity frameworks. Additionally, organizations should consider implementing intrusion detection systems to monitor for unusual telnet activity on port 2000 and establish incident response procedures to quickly address potential exploitation attempts. The vulnerability also underscores the necessity of regular security assessments and vulnerability management processes to identify and remediate similar weaknesses in legacy network security infrastructure.