CVE-2000-1124 in AIX
Summary
by MITRE
Buffer overflow in piobe command in IBM AIX 4.3.x allows local users to gain privileges via long environmental variables.
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Analysis
by VulDB Data Team • 06/05/2024
The vulnerability described in CVE-2000-1124 represents a critical buffer overflow flaw within the piobe command of IBM AIX 4.3.x operating systems. This issue specifically affects local users who can exploit the vulnerability by providing excessively long environmental variables to trigger the buffer overflow condition. The piobe command, which is part of the AIX operating system's administrative utilities, handles printer output buffering operations and is designed to process environmental variables containing printer configuration information. When these environmental variables exceed the allocated buffer space, the overflow condition occurs, potentially allowing attackers to execute arbitrary code with elevated privileges.
The technical implementation of this vulnerability stems from inadequate input validation within the piobe command's handling of environmental variables. The command fails to properly check the length of environmental variable values before copying them into fixed-size buffers, creating a classic buffer overflow scenario. This flaw operates at the system level where local users can manipulate environmental variables to exceed buffer boundaries, causing memory corruption that can be exploited to overwrite critical program execution structures. The vulnerability is particularly dangerous because it allows privilege escalation from regular user level to root privileges, making it a significant security risk for systems running IBM AIX 4.3.x versions.
From an operational impact perspective, this vulnerability creates substantial risks for organizations using IBM AIX 4.3.x systems, as local attackers can leverage it to gain unauthorized administrative access. The exploit requires minimal prerequisites since it only needs local user access and the ability to set environmental variables, making it relatively easy to exploit in practice. Once successfully exploited, the vulnerability enables attackers to execute arbitrary code with root privileges, potentially leading to complete system compromise, data theft, or persistent backdoor establishment. The impact extends beyond individual system compromise to affect overall network security posture, as compromised systems can serve as launch points for further attacks within the network infrastructure.
The vulnerability aligns with CWE-121, which categorizes buffer overflow conditions as critical weaknesses in software design that can lead to arbitrary code execution. This classification reflects the fundamental nature of the flaw where insufficient bounds checking in memory operations creates opportunities for attackers to manipulate program execution flow. From the MITRE ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and the use of system utilities for malicious purposes. The attack vector involves local user execution and environmental variable manipulation, which corresponds to techniques used in the privilege escalation and persistence phases of the attack lifecycle. Organizations should implement immediate mitigations including patching the affected AIX systems to the latest security updates, restricting local user access where possible, and monitoring for suspicious environmental variable usage patterns. Additionally, system administrators should consider implementing proper input validation controls and memory protection mechanisms to prevent similar vulnerabilities from manifesting in other system components.