CVE-2004-2686 in Solaris
Summary
by MITRE
Directory traversal vulnerability in the vfs_getvfssw function in Solaris 2.6, 7, 8, and 9 allows local users to load arbitrary kernel modules via crafted (1) mount or (2) sysfs system calls. NOTE: this might be the same issue as CVE-2004-1767, but there are insufficient details to be sure.
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Analysis
by VulDB Data Team • 07/01/2025
The vulnerability described in CVE-2004-2686 represents a critical directory traversal flaw within the Solaris operating system kernel, specifically affecting versions 2.6 through 9. This weakness resides in the vfs_getvfssw function which handles virtual file system operations, creating an opportunity for local attackers to escalate privileges by loading unauthorized kernel modules. The vulnerability stems from insufficient input validation in system calls that interact with the virtual file system layer, allowing malicious actors to manipulate kernel module loading through carefully crafted mount or sysfs operations. The flaw essentially permits an attacker to bypass normal kernel module security controls and execute arbitrary code within the kernel context, potentially leading to complete system compromise.
The technical implementation of this vulnerability involves the improper handling of path traversal sequences within the virtual file system switching mechanism. When the vfs_getvfssw function processes system calls, it fails to adequately sanitize input parameters that specify file system types or module paths. This weakness enables attackers to construct malicious paths that traverse directories outside of intended boundaries, ultimately allowing them to load kernel modules from arbitrary locations on the filesystem. The vulnerability specifically affects the mount system call and sysfs operations, both of which are legitimate kernel interfaces that should normally be restricted from loading unauthorized modules. The flaw can be exploited through local user accounts with minimal privileges, making it particularly dangerous as it requires no network access or special permissions beyond basic user-level access.
The operational impact of CVE-2004-2686 is severe and far-reaching, as it provides local attackers with a pathway to kernel-level privilege escalation. Once exploited, the vulnerability allows attackers to load malicious kernel modules that can manipulate system memory, intercept network traffic, or disable security mechanisms entirely. This capability fundamentally undermines the security model of Solaris systems, as kernel modules operate with the highest privileges and can directly control system resources. The vulnerability affects multiple generations of Solaris releases, indicating a long-standing issue that persisted across several versions, suggesting the flaw was deeply embedded in the kernel's virtual file system handling code. Systems running affected Solaris versions are particularly vulnerable in environments where local access is possible, such as shared systems or those with compromised user accounts.
Mitigation strategies for this vulnerability require immediate patching of affected Solaris systems with the appropriate security updates from Oracle. Organizations should prioritize updating all systems running Solaris 2.6 through 9 to the latest security patches available from the vendor. Additionally, system administrators should implement strict access controls to limit local user privileges and monitor for unauthorized kernel module loading activities. The vulnerability aligns with CWE-22 Directory Traversal and CWE-436 Interpretation Conflict, as it involves improper path handling and kernel module interpretation issues. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques using kernel exploits, specifically T1068 and T1543. System hardening measures should include disabling unnecessary system calls and implementing kernel module signing requirements to prevent unauthorized module loading. Regular security audits and monitoring of kernel module activities should be conducted to detect potential exploitation attempts and maintain system integrity against this and similar vulnerabilities.