CVE-2004-0618 in FreeBSD
Summary
by MITRE
FreeBSD 5.1 for the Alpha processor allows local users to cause a denial of service (crash) via an execve system call with an unaligned memory address as an argument.
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Analysis
by VulDB Data Team • 09/26/2024
The vulnerability identified as CVE-2004-0618 represents a critical denial of service weakness in FreeBSD version 5.1 specifically affecting the Alpha processor architecture. This flaw manifests when a local attacker executes an execve system call with an unaligned memory address as one of the arguments, causing the operating system kernel to crash and subsequently resulting in a system-wide denial of service condition. The issue stems from insufficient memory alignment validation within the kernel's handling of system calls, particularly those involving executable file loading operations.
The technical root cause of this vulnerability lies in the kernel's failure to properly validate memory address alignment during execve system call processing. When an unaligned memory address is passed as an argument to execve, the Alpha processor architecture's memory management unit cannot properly handle the misaligned access, leading to a kernel panic and system crash. This represents a classic case of improper input validation and memory handling, categorized under CWE-121 in the Common Weakness Enumeration taxonomy. The vulnerability specifically affects the kernel's memory management subsystem and demonstrates poor error handling in low-level system operations.
From an operational impact perspective, this vulnerability presents a significant threat to FreeBSD systems running on Alpha processors, as local users can reliably trigger system crashes without requiring elevated privileges. The attack vector is particularly concerning because it requires only local access to the system, making it exploitable by any user with login credentials. The resulting denial of service can disrupt critical system operations, potentially affecting services, applications, and user access. In enterprise environments, this vulnerability could be leveraged to disrupt operations or create opportunities for further attacks, as system administrators may be forced to restart services or reboot systems.
The mitigation strategies for this vulnerability primarily involve applying the official FreeBSD security patches released in response to this issue. System administrators should immediately update their FreeBSD installations to versions containing the necessary kernel fixes that properly validate memory address alignment during execve operations. Additionally, implementing proper system monitoring and alerting mechanisms can help detect unusual system crashes that might indicate exploitation attempts. Network segmentation and privilege separation practices can also reduce the potential impact of local exploitation. This vulnerability aligns with ATT&CK technique T1499.004 which covers network denial of service attacks, though in this case the attack is executed locally rather than remotely. Organizations should also consider implementing kernel hardening measures such as stack canaries, address space layout randomization, and other memory protection mechanisms to reduce the overall attack surface and improve system resilience against similar memory-related vulnerabilities.