CVE-1999-0860 in Solaris
Summary
by MITRE
Solaris chkperm allows local users to read files owned by bin via the VMSYS environmental variable and a symlink attack.
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Analysis
by VulDB Data Team • 12/30/2024
The vulnerability described in CVE-1999-0860 resides within the Solaris operating system's chkperm utility, which is designed to check file permissions and verify access controls. This flaw represents a classic privilege escalation vulnerability that exploits the insecure handling of environment variables and symbolic links within the system's file access mechanisms. The chkperm utility operates with elevated privileges to perform permission checks on system files, making it a potential target for local attackers seeking to bypass security controls.
The technical implementation of this vulnerability leverages the VMSYS environmental variable, which is typically used to specify the location of virtual memory system files in Solaris environments. When chkperm processes this variable, it fails to properly validate or sanitize the path references, creating an opportunity for attackers to manipulate the utility's behavior through symbolic link manipulation. Local users can create symbolic links that point to sensitive files owned by the bin user account, which typically represents system binaries with specific permission requirements. The vulnerability stems from the utility's failure to resolve paths through proper access control checks before following symbolic links, allowing attackers to traverse the file system in unintended ways.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it enables attackers to read files that should normally be restricted to specific user groups or system processes. Files owned by the bin user account often contain critical system information, configuration data, or potentially sensitive binaries that could be exploited for further system compromise. This vulnerability directly violates the principle of least privilege and creates a pathway for attackers to bypass mandatory access controls that should protect system integrity. The attack vector requires local access to the system, making it particularly concerning for environments where privilege separation is critical for security.
From a cybersecurity perspective, this vulnerability aligns with CWE-59 and CWE-22 categories, which address improper handling of symbolic links and path traversal issues respectively. The attack pattern corresponds to techniques described in the MITRE ATT&CK framework under T1068, which covers local privilege escalation through exploitation of system vulnerabilities. The vulnerability demonstrates a fundamental flaw in how the Solaris system handles environment variable processing and symbolic link resolution, creating an attack surface that could be exploited by adversaries with minimal privileges to gain access to restricted resources. Organizations should implement immediate mitigations including restricting access to the chkperm utility, validating environment variables through proper access controls, and ensuring that symbolic links are properly resolved with appropriate privilege checks before file access operations are performed.