CVE-2001-0797 in HP-UX
Summary
by MITRE
Buffer overflow in login in various System V based operating systems allows remote attackers to execute arbitrary commands via a large number of arguments through services such as telnet and rlogin.
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Analysis
by VulDB Data Team • 10/04/2025
The vulnerability described in CVE-2001-0797 represents a critical buffer overflow flaw within the login service of System V based operating systems that has significant implications for remote command execution capabilities. This vulnerability specifically affects the handling of command line arguments during the authentication process, creating a pathway for malicious actors to exploit the system's security boundaries. The issue manifests when the login service receives an excessive number of arguments through network services such as telnet and rlogin, which are fundamental components of Unix and Unix-like operating systems for remote access and administration.
The technical implementation of this buffer overflow stems from inadequate input validation and bounds checking within the login utility's argument parsing mechanism. When remote services like telnet or rlogin invoke the login program, they pass command line arguments that are not properly sanitized or constrained in length. The login program's internal buffer allocation does not adequately account for the potential size of these arguments, leading to memory corruption that can be exploited to overwrite critical program execution elements. This flaw operates at the system level where the login service typically runs with elevated privileges, making the potential impact substantially more severe than typical user-level vulnerabilities.
The operational impact of CVE-2001-0797 extends beyond simple privilege escalation to encompass full system compromise capabilities. Attackers can leverage this vulnerability to execute arbitrary code with the privileges of the login service, which typically runs with root or administrative privileges on affected systems. The attack vector through telnet and rlogin services means that systems exposed to the internet or untrusted networks are particularly vulnerable, as these services are commonly enabled and accessible. This vulnerability directly maps to CWE-121, which describes heap-based buffer overflow conditions, and aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' through the exploitation of system-level vulnerabilities.
Mitigation strategies for this vulnerability require immediate patching of affected systems through vendor-provided security updates that address the buffer overflow in the login service implementation. System administrators should also implement network segmentation to limit access to telnet and rlogin services, while considering the deployment of more secure remote access protocols such as SSH. The vulnerability's nature makes it particularly dangerous for systems that rely on legacy network services, as the exploitation can occur without requiring authentication or specific user interaction. Regular security audits should verify that all login-related services properly validate input parameters and implement proper bounds checking to prevent similar buffer overflow conditions from occurring in other system components.
The broader implications of this vulnerability highlight the critical importance of secure coding practices in system-level utilities and the necessity of thorough input validation across all security-critical code paths. This flaw demonstrates how seemingly minor implementation details in core system services can create significant security risks that persist across multiple operating system generations. Organizations should implement comprehensive security monitoring to detect exploitation attempts and maintain up-to-date vulnerability assessments to identify similar buffer overflow conditions in other system components that may present comparable risks. The vulnerability serves as a reminder that legacy services and their implementation details can harbor security flaws that remain exploitable for years after initial deployment, emphasizing the need for continuous security maintenance and proactive vulnerability management programs.