CVE-2005-4271 in AIX
Summary
by MITRE
Buffer overflow in the malloc debug system in IBM AIX 5.3 allows local users to execute arbitrary code.
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Analysis
by VulDB Data Team • 08/29/2019
The vulnerability identified as CVE-2005-4271 represents a critical buffer overflow condition within the malloc debug system of IBM AIX 5.3 operating system. This flaw exists in the memory allocation debugging mechanisms that are typically used for development and testing purposes but can be exploited in production environments when enabled. The vulnerability stems from inadequate bounds checking in the malloc debug implementation, specifically when handling memory allocation requests that exceed predetermined buffer limits. Attackers can leverage this weakness to overwrite adjacent memory locations, potentially corrupting program execution flow and gaining unauthorized access to system resources.
The technical nature of this vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite memory regions. The flaw occurs within the malloc debugging subsystem that is part of the standard AIX runtime environment, making it particularly dangerous as it operates at a fundamental level of memory management. When local users execute programs that trigger the debug system, they can craft malicious input that causes the buffer overflow to occur in the malloc debug code paths. This creates an execution environment where arbitrary code can be injected and executed with the privileges of the affected process, potentially escalating to system-level access.
The operational impact of CVE-2005-4271 extends beyond simple code execution as it provides attackers with persistent access to systems running IBM AIX 5.3 with debug features enabled. Local privilege escalation becomes possible through this vulnerability, allowing attackers to execute malicious code with elevated privileges. The attack vector requires local access to the system, meaning an attacker must already have user-level access to exploit the vulnerability, but once successful, the consequences can be severe. The vulnerability affects systems where malloc debug functionality is enabled, which is typically found in development and testing environments but may also be active in production systems for troubleshooting purposes. This creates a significant risk for organizations that maintain debug configurations in their production environments.
Mitigation strategies for CVE-2005-4271 focus on disabling debug features in production environments and applying appropriate system hardening measures. Organizations should disable malloc debug functionality when not actively debugging applications, as this eliminates the attack surface for this specific vulnerability. System administrators should implement strict access controls to prevent unauthorized local users from executing programs that could trigger the vulnerable code paths. The recommended approach involves patching the affected AIX versions through IBM security updates, which address the buffer overflow conditions in the malloc debug implementation. Additionally, implementing proper input validation and bounds checking in applications can help prevent exploitation attempts, though this requires code-level modifications. Security monitoring should include detection of unusual malloc debug activity patterns that could indicate attempted exploitation of this vulnerability. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting the execution of malicious code through memory corruption vulnerabilities. Organizations should also consider implementing runtime protection mechanisms such as stack canaries and address space layout randomization to further reduce the exploitability of similar buffer overflow conditions.