CVE-2007-5159 in ntfs-3g
Summary
by MITRE
The ntfs-3g package before 1.913-2.fc7 in Fedora 7, and an ntfs-3g package in Ubuntu 7.10/Gutsy, assign incorrect permissions (setuid root) to mount.ntfs-3g, which allows local users with fuse group membership to read from and write to arbitrary block devices, possibly involving a file descriptor leak.
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Analysis
by VulDB Data Team • 07/29/2021
The vulnerability identified as CVE-2007-5159 represents a critical privilege escalation flaw within the ntfs-3g filesystem driver package that affected multiple Linux distributions including Fedora 7 and Ubuntu 7.10. This issue stems from improper permission assignment during the installation process where the mount.ntfs-3g utility is incorrectly configured with setuid root permissions. The flaw creates a dangerous condition where local users who belong to the fuse group can exploit this misconfiguration to gain unauthorized access to arbitrary block devices on the system. The vulnerability operates at the kernel level filesystem interface, specifically targeting the NTFS filesystem support mechanism that relies on the fuse (Filesystem in Userspace) framework for operation.
The technical implementation of this vulnerability involves a fundamental flaw in the permission model of the ntfs-3g package where the mount.ntfs-3g binary is granted root privileges through setuid bit execution. When users with fuse group membership execute this utility, they can leverage the elevated permissions to perform operations that should normally be restricted to root level processes. This creates a path for arbitrary block device access where malicious users can read from and write to any block device on the system, effectively bypassing normal filesystem access controls. The vulnerability is particularly dangerous because it operates through the FUSE framework which is designed to allow non-privileged users to create their own filesystem implementations, but in this case the utility itself has been incorrectly configured to maintain root privileges.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential data compromise and system integrity violations. Local attackers with fuse group membership can access sensitive system files, modify critical system components, and potentially establish persistence mechanisms through manipulation of block devices. The file descriptor leak aspect of this vulnerability compounds the risk by potentially allowing continued access to system resources even after initial exploitation attempts. This vulnerability aligns with CWE-276, which addresses improper permissions in Unix systems, and represents a classic example of privilege escalation through insecure file permissions. The attack vector follows ATT&CK technique T1068, which involves exploiting local privileges to escalate access and gain unauthorized system control.
Mitigation strategies for this vulnerability require immediate patching of the affected ntfs-3g packages to correct the permission settings on the mount.ntfs-3g binary. System administrators should verify that the setuid bit has been properly removed from the mount.ntfs-3g utility and that appropriate access controls have been implemented to prevent unauthorized execution with elevated privileges. The recommended remediation involves updating to ntfs-3g package versions 1.913-2.fc7 or later for Fedora 7 systems and the corresponding Ubuntu 7.10 patches. Additionally, system hardening measures should include monitoring for unauthorized execution of the mount.ntfs-3g utility and implementing proper access controls for the fuse group membership to prevent unauthorized users from gaining access to potentially dangerous filesystem operations. Organizations should also consider implementing process monitoring to detect suspicious activity related to block device access and filesystem mounting operations that could indicate exploitation attempts.