CVE-2001-1415 in OpenBSD
Summary
by MITRE
vi.recover in OpenBSD before 3.1 allows local users to remove arbitrary zero-byte files such as device nodes.
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Analysis
by VulDB Data Team • 11/13/2024
The vulnerability described in CVE-2001-1415 affects the vi.recover utility in OpenBSD systems prior to version 3.1, representing a significant local privilege escalation risk that leverages improper file handling mechanisms within the system's text editor recovery functionality. This flaw specifically targets the vi.recover component which is designed to restore unsaved changes to files when the vi editor crashes or is terminated unexpectedly. The vulnerability arises from insufficient validation of file operations during the recovery process, allowing malicious local users to exploit the utility's behavior to remove zero-byte files including critical device nodes that form part of the system's filesystem structure.
The technical implementation of this vulnerability stems from the improper handling of file removal operations within the vi.recover utility's recovery mechanisms. When the recovery process attempts to manage temporary files or restore data, it fails to properly validate the target files being manipulated, particularly those with zero-byte characteristics. This validation gap enables attackers to craft specific file operations that cause the recovery utility to inadvertently execute removal commands against device nodes or other critical zero-byte files. The flaw operates at the system call level where file operations are processed without adequate permission checking or file type validation, creating an attack surface that can be exploited through carefully constructed file manipulation sequences.
From an operational perspective, this vulnerability presents a severe risk to system integrity as it allows local users to remove critical device nodes that are essential for proper system operation. Device nodes such as /dev/null, /dev/zero, or other special device files can be targeted through this mechanism, potentially leading to system instability, service disruption, or complete system compromise. The impact extends beyond simple file removal since device nodes are fundamental components of Unix-like operating systems, and their removal can affect system functionality, logging capabilities, and overall system stability. Attackers could leverage this vulnerability to create persistent access points or to disable critical system services by removing essential device files required for normal system operation.
The vulnerability aligns with CWE-22, which addresses improper limitation of a pathname to a restricted directory, and represents a specific instance of inadequate input validation within system utilities. It also maps to ATT&CK technique T1068, which covers the use of local privilege escalation techniques through exploitation of system utilities. The attack vector requires local system access, making it particularly concerning for multi-user environments where privilege separation is crucial for maintaining system security. Organizations using OpenBSD versions prior to 3.1 should consider this vulnerability as part of their broader security posture assessment, particularly in environments where multiple users have access to system resources.
Mitigation strategies for this vulnerability primarily focus on upgrading to OpenBSD 3.1 or later versions where the issue has been addressed through proper file validation and handling mechanisms. System administrators should also implement additional security measures such as restricting access to the vi.recover utility, monitoring file system changes, and conducting regular security audits to identify potential exploitation attempts. The fix implemented by OpenBSD developers involved strengthening the validation of file operations within the recovery utility, ensuring that only appropriate files are manipulated during the recovery process. Additionally, organizations should consider implementing privilege separation mechanisms and access controls to limit the potential impact of local users who might attempt to exploit this vulnerability, particularly in shared computing environments where multiple users require different levels of system access.