CVE-2000-0795 in IRIX
Summary
by MITRE
Buffer overflow in lpstat in IRIX 6.2 and 6.3 allows local users to gain root privileges via a long -n option.
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Analysis
by VulDB Data Team • 10/10/2024
The vulnerability identified as CVE-2000-0795 represents a critical buffer overflow flaw within the lpstat utility of IRIX operating systems version 6.2 and 6.3. This issue resides in the command-line argument processing mechanism where the -n option fails to properly validate input length, creating an exploitable condition that can be leveraged by local attackers to escalate privileges to root level access. The lpstat utility is part of the printing subsystem and is commonly used to query printer status and job information, making it a frequently accessed system tool that presents an attractive target for privilege escalation attacks.
The technical implementation of this vulnerability stems from improper bounds checking within the lpstat program's argument parsing code. When processing the -n option, the software does not adequately verify the length of the input parameter against the allocated buffer space, allowing an attacker to overflow the buffer and overwrite adjacent memory locations. This classic buffer overflow condition can be exploited to overwrite the return address on the stack, redirecting program execution flow to malicious code that has been crafted to execute with elevated privileges. The vulnerability specifically affects the local user context, meaning that an attacker must already have access to a user account on the system to exploit this flaw, though the ultimate goal is to achieve root privileges through the privilege escalation mechanism.
The operational impact of this vulnerability extends beyond simple local privilege escalation, as it represents a significant security weakness in the system's access control mechanisms. Attackers who successfully exploit this vulnerability can gain complete administrative control over the affected IRIX systems, potentially leading to data compromise, system destruction, or use as a foothold for further network infiltration. The vulnerability affects systems running IRIX 6.2 and 6.3 versions, which were widely deployed in enterprise environments during the late 1990s and early 2000s, making this a potentially widespread concern for organizations maintaining legacy systems. The local nature of the attack reduces detection difficulty compared to remote exploits, as the attacker does not need to bypass network security controls or perform complex reconnaissance.
From a cybersecurity perspective, this vulnerability aligns with CWE-121, which categorizes stack-based buffer overflow conditions, and demonstrates the classic attack pattern described in the ATT&CK framework under privilege escalation techniques. The exploitability of this vulnerability is enhanced by the fact that lpstat is typically installed with setuid root permissions, which means that even when executed by a regular user, the program runs with root privileges. This design pattern, while necessary for proper system functionality, creates a dangerous attack surface when combined with buffer overflow vulnerabilities. Organizations should implement immediate mitigations including patching the affected IRIX systems, removing or restricting access to the vulnerable lpstat utility, and monitoring for unauthorized local access attempts. The vulnerability also underscores the importance of proper input validation and bounds checking in system utilities, particularly those with elevated privileges, as highlighted in various security standards and best practices for secure coding practices.
The remediation approach for this vulnerability requires immediate system patching through official IRIX updates from silicon graphics, as well as implementation of access controls that limit local user privileges where possible. System administrators should conduct comprehensive vulnerability assessments to identify other potentially vulnerable setuid utilities and ensure that proper input validation is implemented throughout the system's command-line interfaces. Additionally, monitoring solutions should be deployed to detect unusual usage patterns of the lpstat utility, particularly when executed with long argument strings, as this could indicate exploitation attempts. The vulnerability serves as a historical example of how seemingly minor programming errors in system utilities can create significant security risks, emphasizing the critical importance of secure coding practices and thorough code review processes for all system components, especially those with elevated privileges.