CVE-2000-1125 in restore
Summary
by MITRE
restore 0.4b15 and earlier in Red Hat Linux 6.2 trusts the pathname specified by the RSH environmental variable, which allows local users to obtain root privileges by modifying the RSH variable to point to a Trojan horse program.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 12/01/2024
The vulnerability described in CVE-2000-1125 represents a critical privilege escalation flaw in the restore utility version 0.4b15 and earlier distributed with Red Hat Linux 6.2. This issue stems from the restore program's improper handling of the RSH environment variable, which is typically used to specify the remote shell command for network operations. The flaw allows local attackers to manipulate the execution flow of the restore utility by modifying the RSH variable to reference a malicious Trojan horse program, thereby gaining unauthorized root privileges on the affected system.
The technical root cause of this vulnerability lies in the insecure handling of environment variables within the restore utility. When the restore program executes, it relies on the RSH environment variable to determine which remote shell command to use for network operations. However, the program does not properly validate or sanitize this variable, allowing attackers to inject arbitrary commands through manipulation of the environment variable. This design flaw directly maps to CWE-78, which describes improper neutralization of special elements used in OS commands, and CWE-276, which addresses incorrect permissions for critical resources.
The operational impact of this vulnerability is severe as it provides local users with a straightforward path to achieve root privileges without requiring any special authentication or network access. Attackers need only modify the RSH environment variable to point to a crafted Trojan horse program that executes with elevated privileges when the restore utility runs. This type of vulnerability is particularly dangerous because it can be exploited by any user with local access to the system, making it a significant concern for system administrators who must trust all local users. The attack vector aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' through local system exploitation methods.
The exploitability of this vulnerability is enhanced by the fact that restore utilities are commonly used for system administration tasks, making them accessible to users who may not have direct root access. This creates a dangerous situation where a simple environment variable modification can result in complete system compromise. The vulnerability demonstrates poor input validation and privilege management practices that were common in system utilities of that era. System administrators should consider implementing additional security measures such as restricting access to critical system utilities, monitoring for unauthorized environment variable modifications, and ensuring that all system utilities are regularly updated to patched versions. The remediation approach involves updating to a patched version of the restore utility where the RSH environment variable is properly validated or eliminated from the execution path, thus preventing the arbitrary command execution that leads to privilege escalation.