CVE-2007-2654 in xfsdump
Summary
by MITRE
xfs_fsr in xfsdump creates a .fsr temporary directory with insecure permissions, which allows local users to read or overwrite arbitrary files on xfs filesystems.
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Analysis
by VulDB Data Team • 07/21/2019
The vulnerability identified as CVE-2007-2654 resides within the xfs_fsr utility component of the xfsdump package, which is part of the XFS filesystem implementation for Linux operating systems. This flaw manifests in the improper handling of temporary directory creation during filesystem operations, specifically when the utility needs to perform file system resizing or related maintenance tasks. The xfs_fsr utility is designed to optimize XFS filesystems by reorganizing files and improving space allocation efficiency, but it introduces a critical security weakness in its temporary file handling mechanism.
The technical implementation flaw stems from the xfs_fsr utility creating a temporary directory named .fsr with overly permissive access controls. This insecure permission setting allows local users to manipulate the temporary directory structure and potentially gain unauthorized access to filesystem data. The vulnerability specifically exploits the lack of proper permission validation during temporary directory creation, where the utility defaults to creating directories with world-readable and world-writable permissions instead of implementing restrictive access controls that would prevent unauthorized file system interactions. This weakness operates at the file system level and directly impacts the security boundaries that should exist between different user contexts within the same system.
The operational impact of this vulnerability extends beyond simple information disclosure, as local attackers can leverage the insecure temporary directory to overwrite arbitrary files on the XFS filesystem. This creates a significant risk for system integrity and data confidentiality, particularly in multi-user environments where different users may have varying levels of access privileges. The vulnerability enables privilege escalation scenarios where unprivileged users could potentially modify critical system files or overwrite files belonging to other users, leading to potential system compromise or data corruption. Attackers could exploit this weakness to disrupt normal system operations, gain elevated privileges, or establish persistent access points within the compromised system.
Mitigation strategies for this vulnerability require immediate attention through system updates and configuration hardening measures. The primary remediation involves upgrading to patched versions of the xfsdump package where the temporary directory creation logic has been corrected to implement proper permission settings. System administrators should ensure that all XFS filesystems are running updated software versions that address this specific weakness. Additionally, implementing proper access controls and monitoring for unauthorized temporary directory modifications can provide additional defense layers. The vulnerability aligns with CWE-732, which describes inadequate permissions for critical resources, and represents a clear violation of the principle of least privilege that should be enforced in all system components. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and can be leveraged for persistent access within compromised systems, making it a critical security concern for organizations relying on XFS filesystem implementations.