CVE-2005-0125 in Mac OS X
Summary
by MITRE
the "at" commands on mac os x 10.3.7 and earlier do not properly drop privileges which allows local users to (1) delete arbitrary files via atrm (2) execute arbitrary programs via the -f argument to batch or (3) read arbitrary files via the -f argument to batch which generates a job file that is readable by the local user.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 12/27/2024
The vulnerability described in CVE-2005-0125 represents a critical privilege escalation issue within the at command implementation on Mac OS X 10.3.7 and earlier versions. This flaw stems from improper privilege dropping mechanisms within the system's job scheduling utilities, creating a significant security weakness that local attackers can exploit to gain elevated system access. The at command suite includes multiple utilities such as atrm for removing scheduled jobs, batch for executing commands, and the at command itself for scheduling tasks. The vulnerability specifically affects the batch command's handling of the -f argument and the atrm command's file manipulation capabilities, creating multiple attack vectors for privilege escalation.
The technical flaw manifests in the improper handling of user privileges when executing these commands, particularly during the processing of the -f argument in batch commands and file operations within atrm. When a local user invokes the batch command with the -f argument, the system fails to properly drop elevated privileges before processing the file argument, allowing the user to specify arbitrary file paths that can be read by the local user account. This creates a privilege escalation pathway where an attacker can read files that would normally be restricted. Additionally, the atrm command does not properly validate or sanitize file paths, enabling local users to delete arbitrary files from the system. The root cause of this vulnerability aligns with CWE-276, which addresses improper privileges, and CWE-264, which covers permissions, privileges and access controls.
The operational impact of this vulnerability is substantial as it provides local attackers with multiple attack vectors for system compromise. The ability to delete arbitrary files through atrm can be leveraged to disrupt system operations, remove critical security files, or create denial of service conditions. The batch command's file reading capability allows attackers to extract sensitive information from system files that should be restricted to privileged users. Furthermore, the privilege escalation potential means that local users can execute arbitrary programs with elevated privileges, potentially leading to complete system compromise. This vulnerability directly aligns with ATT&CK technique T1068, which covers privilege escalation through local commands, and T1074, which addresses data staging through file system access.
Mitigation strategies for this vulnerability should focus on immediate system updates and privilege management. The most effective solution involves upgrading to Mac OS X 10.3.8 or later versions where Apple has implemented proper privilege dropping mechanisms for the at command utilities. System administrators should also implement additional controls such as restricting access to the at command utilities through file permissions and monitoring for unauthorized usage patterns. The implementation of discretionary access controls should be strengthened to prevent local users from manipulating scheduled jobs or accessing restricted files through these vulnerable commands. Additionally, security monitoring should be enhanced to detect suspicious usage of the batch and atrm commands, particularly when they are invoked with arguments that could indicate privilege escalation attempts. Organizations should also consider implementing network-based controls to limit local user access to system resources and establish baseline monitoring for file deletion and read operations that could indicate exploitation of this vulnerability.