CVE-2000-1120 in AIX
Summary
by MITRE
Buffer overflow in digest command in IBM AIX 4.3.x and earlier allows local users to execute arbitrary commands.
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Analysis
by VulDB Data Team • 06/05/2024
The vulnerability identified as CVE-2000-1120 represents a critical buffer overflow flaw within the digest command functionality of IBM AIX operating systems version 4.3.x and earlier releases. This security weakness specifically affects the digest command which is part of the AIX operating system's utility suite designed for processing and managing cryptographic digests. The buffer overflow condition occurs when the digest command processes input data without adequate bounds checking, allowing maliciously crafted input to overwrite adjacent memory locations in the program's execution environment. This particular vulnerability resides within the system's command processing mechanism where insufficient validation of user-supplied input parameters creates an exploitable condition that can be leveraged by local attackers with system access.
The technical exploitation of this buffer overflow vulnerability enables local users to execute arbitrary commands with elevated privileges by carefully crafting input that exceeds the allocated buffer size and overflows into adjacent memory regions. When the digest command processes malicious input, it can overwrite the return address on the stack or other critical program variables, allowing an attacker to redirect program execution flow to malicious code placed within the overflowed buffer. This type of vulnerability falls under the Common Weakness Enumeration category CWE-121, which specifically addresses stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite stack memory. The attack vector requires local system access, making it a local privilege escalation vulnerability that can be particularly dangerous in multi-user environments where users might have legitimate access to system utilities but should not possess elevated privileges.
The operational impact of this vulnerability extends beyond simple command execution, as successful exploitation can provide attackers with the ability to escalate privileges and potentially gain root access to the affected AIX systems. This makes the vulnerability particularly concerning for enterprise environments where AIX servers might be running critical applications and services. The local nature of the attack means that any user with access to the system can potentially exploit this weakness, regardless of their initial privilege level. Attackers can leverage this vulnerability to modify system files, install backdoors, or perform other malicious activities that could compromise the integrity and confidentiality of the entire system. The vulnerability also impacts the overall security posture of organizations relying on older AIX versions, as it demonstrates the risks associated with maintaining outdated operating system releases that may contain unpatched security flaws.
Organizations affected by this vulnerability should implement immediate mitigations including applying the relevant IBM security patches and updates that address the buffer overflow condition in the digest command. System administrators should also consider implementing additional security controls such as restricting access to the digest command and other system utilities to minimize potential attack surfaces. The implementation of proper input validation mechanisms and bounds checking in system utilities can prevent similar vulnerabilities from occurring in the future. Security monitoring should be enhanced to detect unusual patterns of command execution that might indicate exploitation attempts. According to the MITRE ATT&CK framework, this vulnerability would be classified under privilege escalation techniques, specifically leveraging weaknesses in system utilities to gain elevated privileges. Organizations should also conduct regular vulnerability assessments and maintain updated security patches to prevent exploitation of similar buffer overflow vulnerabilities that may exist in other system components. The remediation process should include not only patching the specific vulnerability but also reviewing and strengthening overall system security practices to prevent future incidents of this nature.