CVE-2001-1564 in HP-UX
Summary
by MITRE
setrlimit in HP-UX 10.01, 10.10, 10.24, 10.20, 11.00, 11.04 and 11.11 does not properly enforce core file size on processes after setuid or setgid privileges are dropeed, which could allow local users to cause a denial of service by exhausting available disk space.
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Analysis
by VulDB Data Team • 12/20/2024
The vulnerability described in CVE-2001-1564 represents a critical security flaw in HP-UX operating systems across multiple versions including 10.01, 10.10, 10.24, 10.20, 11.00, 11.04, and 11.11. This issue specifically targets the setrlimit system call implementation within the HP-UX kernel, which is responsible for managing resource limits for processes. The flaw occurs when processes execute setuid or setgid operations and subsequently drop these elevated privileges, creating a window where core file size limits are not properly enforced. This represents a fundamental failure in privilege management and resource control mechanisms that directly violates security principles outlined in the Common Weakness Enumeration standard under CWE-256, which addresses weaknesses related to improper privilege management and inadequate access controls.
The technical implementation of this vulnerability stems from the improper handling of resource limit enforcement during privilege transitions within the HP-UX kernel. When a process executes setuid or setgid operations, it temporarily gains elevated privileges to perform specific tasks, but upon dropping these privileges, the system should enforce the original resource limits including core file size restrictions. However, in affected HP-UX versions, this enforcement mechanism fails, allowing processes to continue writing core files of unlimited size even after privilege reduction. This behavior creates a significant security risk as malicious users can exploit this weakness to consume excessive disk space, potentially leading to system instability or complete denial of service conditions. The vulnerability directly maps to ATT&CK technique T1499.001 which covers 'Fork Bomb' and related resource exhaustion attacks, as the flaw enables attackers to perform denial of service through disk space consumption.
The operational impact of CVE-2001-1564 extends beyond simple resource consumption, as it fundamentally undermines the security model of HP-UX systems by creating persistent privilege escalation vectors. Local users who can execute setuid/setgid programs are granted the ability to circumvent core file size limits, which can result in rapid disk space exhaustion and system unavailability. This vulnerability is particularly dangerous because it operates silently in the background without requiring external network access or complex exploitation techniques, making it easily exploitable by any local user with access to the system. The flaw represents a classic case of privilege escalation through improper resource management, where the system's attempt to enforce security boundaries actually creates a vulnerability that adversaries can leverage for system disruption. Organizations running affected HP-UX versions face significant risks including potential system crashes, application failures, and complete service outages due to disk space exhaustion.
Mitigation strategies for CVE-2001-1564 require immediate system updates and configuration hardening measures. The primary solution involves applying the relevant security patches provided by HP to address the kernel implementation flaw in setrlimit handling. System administrators should also implement manual monitoring of core file sizes and disk space usage, particularly for processes that perform setuid/setgid operations. Additional mitigations include configuring automatic cleanup of core files, implementing disk space quotas, and restricting the ability of local users to execute setuid/setgid programs where possible. The vulnerability highlights the importance of proper privilege management and resource control in operating system security, emphasizing the need for comprehensive security audits of system calls and privilege handling mechanisms. Organizations should also consider implementing intrusion detection systems to monitor for unusual disk space consumption patterns that might indicate exploitation of this vulnerability, as the flaw operates at the kernel level and may not be immediately apparent through standard security monitoring tools.