CVE-2000-1122 in AIX
Summary
by MITRE
Buffer overflow in setclock command in IBM AIX 4.3.x and earlier may allow local users to execute arbitrary commands via a long argument.
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Analysis
by VulDB Data Team • 09/04/2019
The vulnerability described in CVE-2000-1122 represents a critical buffer overflow flaw within the setclock command of IBM AIX operating systems version 4.3.x and earlier. This issue arises from insufficient input validation and bounds checking in the command line argument processing mechanism. The setclock utility, designed to configure system clock settings, fails to properly validate the length of user-supplied arguments, creating an exploitable condition that can be leveraged by local attackers with system access. The buffer overflow occurs when a malicious user provides an argument exceeding the allocated buffer space, causing adjacent memory regions to be overwritten with attacker-controlled data.
The technical implementation of this vulnerability aligns with CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking allows memory to be overwritten. The flaw specifically manifests in the command line argument parsing routine where the setclock utility does not implement proper input length validation before copying user-supplied data into fixed-size buffers. Attackers can exploit this by crafting a specially constructed argument that exceeds the buffer capacity, causing a stack-based buffer overflow that can overwrite return addresses and function pointers. This memory corruption enables arbitrary code execution with the privileges of the setclock command, typically running with elevated system privileges.
From an operational perspective, this vulnerability poses significant risk to IBM AIX systems as it allows local users to escalate privileges and execute arbitrary commands on the target system. The exploitation requires only local access, making it particularly dangerous in environments where multiple users share system resources or where privilege escalation opportunities exist. The impact extends beyond simple code execution to potentially enable full system compromise, as the attacker can leverage the elevated privileges to modify system files, install backdoors, or exfiltrate sensitive data. The vulnerability affects systems running IBM AIX 4.3.x and earlier versions, representing a substantial security gap that could be exploited by both malicious insiders and external attackers who have gained local access to the system.
The mitigation strategies for this vulnerability should focus on immediate system updates and patches provided by IBM to address the buffer overflow condition in the setclock command. Organizations must ensure that all affected IBM AIX systems are updated to versions that include proper input validation and bounds checking mechanisms. Additionally, system administrators should implement strict access controls and monitor for unusual command execution patterns that might indicate exploitation attempts. The remediation process should include disabling unnecessary command line utilities and implementing proper input sanitization practices across all system components. This vulnerability demonstrates the critical importance of proper memory management and input validation in system utilities, aligning with ATT&CK technique T1059.003 for command and scripting interpreter execution, where attackers leverage system utilities to execute malicious code through buffer overflow exploitation. Organizations should also consider implementing runtime protection mechanisms and regular security assessments to identify similar vulnerabilities in other system components that might be susceptible to similar buffer overflow attacks.