Source: cve@mitre.org
BuildDisk program on NeXT systems before 2.0 does not prompt users for the root password, which allows local users to gain root privileges.
CVE-1999-1198 exposes a critical vulnerability in NeXT systems, allowing local users to escalate privileges to root without authentication. This flaw, present in the BuildDisk program, bypasses the necessary security checks, enabling unauthorized access and system compromise. Successful exploitation grants complete control over the affected system.
Step 1: Local User Access: A local user logs into the NeXT system.
Step 2: Program Invocation: The local user executes the BuildDisk program.
Step 3: Privilege Escalation: Because BuildDisk does not prompt for a root password, it executes with root privileges.
Step 4: Unauthorized Actions: The user, now effectively root, can perform any operation allowed by the root user, including modifying system files, installing software, or creating new user accounts with elevated privileges.
Step 5: System Compromise: The attacker gains complete control of the system.
The vulnerability stems from a design flaw in the BuildDisk program. Specifically, the program lacks proper authentication checks when invoked by a local user. The program, designed to create disk images, operates with elevated privileges (root) to perform its tasks. The absence of a prompt for the root password allows any local user to execute BuildDisk and perform actions that require root access, effectively bypassing the intended security model. This is a classic example of a privilege escalation vulnerability due to insufficient access control. The root cause is the program's trust in the user's context without verifying their authorization to perform privileged operations.
Due to the age of the vulnerability and the specific target platform, it's unlikely to be actively targeted by sophisticated APTs. However, any attacker with access to a vulnerable system could exploit it. The vulnerability is not listed in the CISA KEV catalog due to its age and the obsolescence of the affected systems.
Monitor system logs for unusual activity related to the BuildDisk program, especially when executed by non-root users.
Analyze system audit logs for unauthorized file modifications or privilege escalation events.
Look for the creation of new user accounts or modifications to existing accounts with elevated privileges.
Network traffic analysis may reveal attempts to access or modify sensitive files or directories after the exploit.
The primary remediation is to upgrade to a version of the NeXT operating system that addresses this vulnerability (version 2.0 or later).
If upgrading is not possible, restrict access to the BuildDisk program to only authorized users.
Implement strong access controls and user authentication mechanisms.
Regularly audit system logs for suspicious activity.
Consider using a host-based intrusion detection system (HIDS) to monitor for unauthorized file modifications or privilege escalation attempts.