CVE-2009-4358 in freebsd
Summary
by MITRE
freebsd-update in FreeBSD 8.0, 7.2, 7.1, 6.4, and 6.3 uses insecure permissions in its working directory (/var/db/freebsd-update by default), which allows local users to read copies of sensitive files after a (1) freebsd-update fetch (fetch) or (2) freebsd-update upgrade (upgrade) operation.
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Analysis
by VulDB Data Team • 01/25/2019
The vulnerability identified as CVE-2009-4358 affects the FreeBSD update mechanism across multiple versions including 8.0, 7.2, 7.1, 6.4, and 6.3. This issue stems from the insecure permissions configured for the working directory utilized by the freebsd-update utility. The default location for this directory is /var/db/freebsd-update, which serves as the storage area for temporary files and update components during the FreeBSD update process. The flaw manifests when the system performs either a fetch operation to retrieve update information or an upgrade operation to apply patches, creating a window of opportunity for local privilege escalation through unauthorized access to sensitive system files.
The technical implementation of this vulnerability involves improper file permission handling within the freebsd-update utility's operational framework. When the utility executes fetch or upgrade commands, it creates temporary files and maintains copies of system components in the designated working directory. These files, which may contain sensitive information such as system configuration details, cryptographic keys, or other privileged data, are stored with permissions that allow any local user to read their contents. This represents a classic case of insecure file permissions that violates fundamental security principles of least privilege and proper access control enforcement. The vulnerability specifically aligns with CWE-732, which addresses incorrect permissions for critical resources, and demonstrates how inadequate permission management can create persistent security weaknesses in system utilities.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables local users to potentially access sensitive system data that could be leveraged for further exploitation. Attackers could utilize this weakness to gather intelligence about the target system, including configuration details that might reveal system architecture, installed packages, or other sensitive metadata. The vulnerability is particularly concerning because it operates at the system level, where the freebsd-update utility typically runs with elevated privileges during update operations, potentially exposing more sensitive data than would be accessible through standard user-level access. This weakness can be exploited by any local user, regardless of their initial privilege level, making it a significant concern for system administrators who must ensure proper access controls across all system components.
Mitigation strategies for CVE-2009-4358 should focus on immediate permission adjustments and system hardening measures. System administrators should verify that the /var/db/freebsd-update directory and its contents are properly secured with restrictive permissions, typically limiting access to root-only operations. The recommended approach involves setting appropriate file permissions that align with the principle of least privilege, ensuring that only authorized system processes and users can access the sensitive update files. Additionally, administrators should consider implementing monitoring mechanisms to detect unauthorized access attempts to the update directory and related files. This vulnerability demonstrates the importance of proper file system security and aligns with ATT&CK technique T1078 which addresses valid accounts and privilege escalation. Organizations should also ensure that their FreeBSD systems are updated to versions that address this specific vulnerability, as the affected versions represent a known security weakness that can be exploited for unauthorized data access and potential privilege escalation within the system environment.