CVE-2010-2961 in mountall
Summary
by MITRE
mountall.c in mountall before 2.15.2 uses 0666 permissions for the root.rules file, which allows local users to gain privileges by modifying this file.
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Analysis
by VulDB Data Team • 11/24/2024
The vulnerability identified as CVE-2010-2961 resides within the mountall utility, a critical component in Debian-based Linux systems responsible for managing filesystem mounting operations during system boot. This flaw affects versions of mountall prior to 2.15.2 and represents a significant privilege escalation risk that exploits improper file permission handling. The vulnerability specifically targets the root.rules file which is created with overly permissive 0666 permissions, allowing any local user to modify this critical system file. The mountall utility, which executes during the boot process, utilizes this root.rules file to determine mount point configurations and access controls, making it a prime target for malicious modification.
The technical implementation of this vulnerability stems from the improper handling of file permissions within the mountall.c source code. When mountall creates the root.rules file, it assigns world-writable permissions (0666) instead of the more secure restricted permissions typically expected for system configuration files. This design flaw enables local users to modify the file contents at any time, potentially inserting malicious mount rules or altering existing configurations. The root.rules file serves as a configuration mechanism for mountall's behavior, and when compromised, it can be leveraged to manipulate how filesystems are mounted, potentially allowing attackers to gain elevated privileges or access restricted system resources. This type of vulnerability aligns with CWE-732, which categorizes improper permission assignment as a critical security weakness.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with a persistent mechanism for system compromise. Local users who can modify the root.rules file can potentially manipulate mount operations to redirect filesystem access, create unauthorized mount points, or even establish backdoor access paths. The vulnerability is particularly dangerous because it operates at the system boot level, meaning that any modifications made to the root.rules file can persist across system reboots. Attackers could use this to create malicious mount configurations that automatically execute code or provide unauthorized access to sensitive system directories. The ATT&CK framework categorizes this as a privilege escalation technique through modification of system files, specifically targeting the T1068 privilege escalation tactic.
Mitigation strategies for CVE-2010-2961 require immediate system updates to version 2.15.2 or later where the vulnerability has been patched. System administrators should verify that the root.rules file now has appropriate permissions, typically restricted to root-only access with 0600 permissions. Additionally, regular security audits should include verification of file permissions for critical system configuration files, particularly those created during system boot processes. The vulnerability highlights the importance of principle of least privilege in system file management and demonstrates how seemingly minor permission issues can create substantial security risks. Organizations should implement automated monitoring tools to detect unauthorized changes to critical system files and establish proper file integrity checking procedures. The remediation process should also include reviewing other system utilities that may create configuration files with overly permissive permissions, as similar vulnerabilities may exist in other components of the system.