CVE-2007-4355 in AIX
Summary
by MITRE
Buffer overflow in the at program on IBM AIX 5.3 allows local users to gain privileges via unspecified vectors.
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Analysis
by VulDB Data Team • 08/23/2019
The vulnerability identified as CVE-2007-4355 represents a critical buffer overflow flaw within the at program component of IBM AIX 5.3 operating system. This issue resides in the local privilege escalation category, where malicious local users can exploit the vulnerability to elevate their access rights and potentially gain administrative privileges on the affected system. The at program serves as a time-based job scheduler that allows users to execute commands or scripts at specified times, making it a critical system component that requires robust security controls. The vulnerability stems from improper input validation and memory management within the program's handling of user-supplied data, creating opportunities for attackers to overwrite memory segments and manipulate program execution flow.
The technical implementation of this buffer overflow vulnerability occurs when the at program processes user input without adequate bounds checking, allowing attackers to supply input data that exceeds the allocated buffer size. This condition enables the execution of arbitrary code with elevated privileges, as the program's memory layout can be manipulated to redirect execution flow toward attacker-controlled code. The vulnerability's impact is particularly severe because it operates within the context of a system utility that typically runs with elevated privileges, providing attackers with a direct path to privilege escalation. The unspecified vectors mentioned in the description suggest that multiple attack surfaces within the at program could potentially trigger the buffer overflow condition, making the vulnerability particularly challenging to fully understand and defend against.
From an operational perspective, this vulnerability creates significant risk for organizations running IBM AIX 5.3 systems, as local users who can access the at program can potentially compromise entire system integrity. The attack requires local system access but does not necessitate network connectivity, making it particularly dangerous in environments where local access is difficult to monitor or control. The privilege escalation capability allows attackers to execute commands with root privileges, potentially enabling them to install backdoors, modify system files, or extract sensitive data. This vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of how improper memory management can lead to severe security consequences. The attack vector can be exploited through various methods including malformed input to the at command, crafted job files, or through other programmatic interfaces that interact with the vulnerable component.
Security practitioners should implement immediate mitigations including applying the relevant IBM AIX security patches and updates that address the buffer overflow condition in the at program. System administrators should also consider disabling the at program if it is not essential for operations, as this eliminates the attack surface entirely. Monitoring for unusual at program usage patterns and implementing discretionary access controls can help detect potential exploitation attempts. The vulnerability demonstrates the importance of proper input validation and memory management practices in system utilities, aligning with ATT&CK technique T1068 which covers privilege escalation through local exploitation. Organizations should conduct comprehensive vulnerability assessments to identify other potentially vulnerable system components and ensure that all system utilities undergo regular security reviews to prevent similar issues. The incident underscores the critical need for maintaining up-to-date system patches and implementing defense-in-depth strategies that reduce the impact of potential local privilege escalation vulnerabilities.