CVE-2007-6285 in Red Hat
Summary
by MITRE
The default configuration for autofs 5 (autofs5) in some Linux distributions, such as Red Hat Enterprise Linux (RHEL) 4 and 5, does not specify the nodev mount option for the -hosts map, which allows local users to access "important devices" by operating a remote NFS server and creating special device files on that server, as demonstrated by the /dev/mem device.
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Analysis
by VulDB Data Team • 06/02/2025
The vulnerability described in CVE-2007-6285 represents a significant security flaw in the autofs5 service configuration that affected major Linux distributions including Red Hat Enterprise Linux 4 and 5. This issue stems from the default autofs configuration that fails to properly enforce mount options, specifically the nodev flag, which is crucial for preventing device file access through mounted filesystems. The vulnerability creates a path for local attackers to exploit the lack of proper mount restrictions, allowing them to gain unauthorized access to critical system devices through remote NFS server manipulation.
The technical flaw manifests in how autofs5 handles mount operations for the -hosts map, which is a critical component of the automounter service responsible for managing network filesystem mounts. When the nodev mount option is not explicitly configured, the system allows device files to be mounted from remote NFS servers, creating a direct pathway to access sensitive device nodes such as /dev/mem. This occurs because the nodev option prevents the interpretation of device files as special device nodes, effectively blocking the ability to access underlying hardware through mounted filesystems. Without this restriction, attackers can create malicious device files on remote NFS servers and mount them locally, thereby gaining access to system-level devices that should remain protected.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential system compromise and data exfiltration capabilities. Local users who can control or influence NFS server configurations can leverage this flaw to access critical system devices that provide direct memory access, hardware control, and other sensitive system resources. The /dev/mem device specifically allows access to physical memory, which can lead to kernel memory disclosure, privilege escalation, and potentially complete system compromise. This vulnerability aligns with CWE-276, which addresses improper privileges, and represents a classic case of insufficient privilege separation in mount operations. The attack vector demonstrates how default configurations can introduce security weaknesses that persist across multiple systems without explicit security hardening.
Mitigation strategies for CVE-2007-6285 require immediate configuration changes to ensure proper mount options are enforced in autofs5 environments. System administrators should explicitly configure the nodev mount option for all autofs5 mount points, particularly the -hosts map, to prevent device file interpretation during mount operations. The recommended approach involves modifying autofs configuration files to include the nodev option in mount parameters, ensuring that device files from remote sources cannot be interpreted as local device nodes. Additionally, organizations should implement comprehensive security auditing procedures to identify and remediate similar configuration weaknesses across their infrastructure. This vulnerability highlights the importance of proper system hardening and the principle of least privilege in mount operations, aligning with ATT&CK technique T1068 which addresses local privilege escalation through improper system configuration. Regular security assessments and configuration management practices should include verification of mount options to prevent similar issues from persisting in updated systems.