CVE-1999-1122 in SunOS
Summary
by MITRE
vulnerability in restore in sunos 4.0.3 and earlier allows local users to gain privileges.
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Analysis
by VulDB Data Team • 04/03/2025
The vulnerability identified as CVE-1999-1122 resides within the restore utility of SunOS 4.0.3 and earlier versions, representing a critical privilege escalation flaw that has persisted in Unix-based operating systems for decades. This vulnerability specifically targets the restore command which is used to restore files from backup archives, and it exploits a fundamental weakness in how the system handles file permissions and ownership during the restoration process. The issue stems from the fact that the restore utility does not properly validate the ownership and permissions of files being restored, allowing local users to manipulate the restoration process to gain elevated privileges. This flaw operates at the system level and represents a classic example of a privilege escalation vulnerability that has been documented in various Unix operating systems throughout the 1990s and beyond.
The technical implementation of this vulnerability involves the restore utility's failure to properly enforce the principle of least privilege during file restoration operations. When a local user executes the restore command, the system does not adequately verify that the restored files maintain their original ownership and permission settings. This oversight creates a path for malicious users to manipulate file attributes during restoration, potentially allowing them to create files with root ownership or execute with elevated privileges. The vulnerability is particularly dangerous because it leverages legitimate system utilities that are typically trusted and have elevated permissions, making it difficult to detect and prevent. This flaw aligns with CWE-276, which addresses improper file permissions and inadequate access control mechanisms in system utilities. The restoration process in SunOS 4.0.3 and earlier versions does not properly validate the integrity of restored file attributes, creating an attack surface that can be exploited to subvert the system's security model.
The operational impact of CVE-1999-1122 extends far beyond simple privilege escalation, as it fundamentally undermines the security architecture of affected SunOS systems. Local users who exploit this vulnerability can gain root access to the system, enabling them to modify critical system files, install malicious software, or establish persistent backdoors. This privilege escalation capability makes the vulnerability particularly attractive to attackers who may be seeking to compromise entire network infrastructures. The vulnerability affects systems that rely on the restore utility for backup operations, which are common in enterprise environments where system administrators regularly use this tool to maintain system integrity. The attack vector is relatively straightforward, requiring only local access to the system, which means that any user with access to the machine can potentially exploit this flaw. This vulnerability demonstrates how seemingly benign system utilities can contain critical security flaws that can be weaponized to gain complete system control, and it highlights the importance of proper input validation and access control enforcement in system utilities. The impact is consistent with ATT&CK technique T1068, which involves local privilege escalation through exploitation of system utilities and the manipulation of file permissions and ownership.
Mitigation strategies for CVE-1999-1122 require immediate system updates and administrative actions to prevent exploitation. The most effective solution is to upgrade to SunOS versions that contain patches addressing this specific vulnerability, as Sun released updated versions of the restore utility that properly validate file ownership and permissions during restoration. System administrators should also implement additional security measures such as restricting access to the restore utility, monitoring for unauthorized usage of the command, and ensuring that only authorized personnel have local access to systems. The implementation of proper file system permissions and the principle of least privilege should be enforced across all system utilities to prevent similar vulnerabilities from being exploited. Additionally, organizations should conduct regular security audits to identify and remediate similar issues in other system utilities, as this vulnerability represents a broader class of problems that can affect various system tools. The vulnerability serves as a reminder of the importance of maintaining up-to-date system software and the critical need for thorough security testing of system utilities, particularly those that operate with elevated privileges. Organizations should also consider implementing automated monitoring solutions to detect unauthorized usage of potentially vulnerable system commands and establish incident response procedures to address exploitation attempts.