CVE-2010-0791 in ncpfs
Summary
by MITRE
The (1) ncpmount, (2) ncpumount, and (3) ncplogin programs in ncpfs 2.2.6 do not properly create lock files, which allows local users to cause a denial of service (application failure) via unspecified vectors that trigger the creation of a /etc/mtab~ file that persists after the program exits.
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Analysis
by VulDB Data Team • 05/02/2026
The vulnerability identified as CVE-2010-0791 affects the ncpfs package version 2.2.6, specifically targeting three critical utility programs: ncpmount, ncpumount, and ncplogin. This issue represents a significant security flaw in the network file system implementation that governs Novell Netware file sharing protocols on unix-like systems. The vulnerability manifests through improper handling of lock file creation mechanisms during the execution of these programs, creating persistent system artifacts that can be exploited by local attackers to disrupt normal system operations. The ncpfs package serves as a crucial bridge for connecting unix-based systems to Novell Netware file servers, making this vulnerability particularly concerning for enterprise environments that rely on distributed file sharing solutions. The flaw exists within the core operational logic of these utilities, which are responsible for mounting, unmounting, and authenticating network file systems.
The technical root cause of this vulnerability lies in the inadequate implementation of file locking mechanisms within the ncpfs utilities. When these programs execute, they attempt to create lock files to prevent concurrent access conflicts, but fail to properly manage the cleanup process for these temporary files. Specifically, the system creates a backup file named /etc/mtab~ during program execution, which should normally be removed upon successful completion but persists even after program termination. This persistent file creation represents a failure in proper resource management and process cleanup protocols. The vulnerability operates through unspecified vectors that trigger the problematic file creation sequence, allowing attackers to manipulate the system state in ways that can lead to application failure and denial of service conditions. The flaw demonstrates poor adherence to secure coding practices and proper file system interaction protocols that are fundamental to system stability and security.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially compromise the overall stability and reliability of systems utilizing ncpfs. Local users with minimal privileges can exploit this weakness to cause applications to fail, effectively disrupting file sharing services and potentially affecting other system components that depend on proper mtab file management. The persistence of the /etc/mtab~ file creates a condition where subsequent operations might encounter conflicts or errors due to the presence of stale file system metadata. This vulnerability can be particularly problematic in enterprise environments where multiple users might interact with the same network file systems, as it allows for cascading failures that could affect broader network operations. The impact is amplified because these utilities are fundamental to network file system operations, making the disruption of any one component potentially devastating to the entire file sharing infrastructure.
Mitigation strategies for CVE-2010-0791 should focus on immediate patching of the ncpfs package to version 2.2.7 or later, which contains the necessary fixes for proper lock file handling and cleanup procedures. System administrators should implement monitoring for the presence of /etc/mtab~ files and establish automated cleanup procedures to address any persistent artifacts. The vulnerability aligns with CWE-367, which addresses Time-of-Check to Time-of-Use (TOCTOU) flaws, and represents a classic example of improper resource management that can lead to denial of service conditions. Organizations should also consider implementing privilege separation mechanisms and access controls to limit local user capabilities that could exploit this vulnerability. Additionally, the ATT&CK framework categorizes this issue under privilege escalation and denial of service tactics, as local users can leverage this weakness to disrupt system services. Regular system audits should verify that proper cleanup procedures are in place and that no stale lock files persist after program execution, ensuring that the system maintains proper file system integrity and operational stability.