Source: cve@mitre.org
chroot in Digital Ultrix 4.1 and 4.0 is insecurely installed, which allows local users to gain privileges.
Digital Ultrix 4.1 and 4.0 systems are vulnerable to a local privilege escalation due to an insecurely configured chroot environment. This allows attackers to bypass intended security boundaries and gain root access, potentially leading to complete system compromise and data exfiltration. This vulnerability, though old, highlights the importance of proper system configuration and security best practices.
Step 1: Initial Access: A local user gains access to the vulnerable Ultrix system, either through a legitimate account or by exploiting another vulnerability.
Step 2: Chroot Environment Exploitation: The attacker identifies the insecurely configured chroot environment.
Step 3: Privilege Escalation: The attacker leverages the flaws in the chroot implementation, such as improper handling of device files or shared libraries, to escape the chroot jail.
Step 4: Root Access: The attacker successfully gains root privileges, allowing them to execute arbitrary commands with elevated privileges.
Step 5: System Compromise: With root access, the attacker can modify system files, install backdoors, steal sensitive data, and potentially control the entire system.
The vulnerability stems from the insecure implementation of the chroot command within Digital Ultrix 4.1 and 4.0. The chroot command is designed to change the apparent root directory for a process, creating a sandboxed environment. However, the Ultrix implementation likely fails to properly sanitize or restrict access to critical system resources within the chroot environment. This could involve issues like improper handling of device nodes, shared libraries, or the ability to escape the chroot jail. The root cause is likely a combination of insufficient access control and a lack of secure configuration of the chroot environment, allowing attackers to manipulate the system's file system and gain elevated privileges. The specific flaw could be related to the way the system handles the creation of device files, access to the /proc filesystem, or the ability to load malicious shared libraries within the chroot environment.
Due to the age of the vulnerability and the specific target (Digital Ultrix), it is unlikely to be actively targeted by sophisticated APTs. However, any attacker with access to an Ultrix system would likely attempt to exploit this vulnerability. This vulnerability is not listed in the CISA KEV catalog due to its age and the rarity of vulnerable systems.
Review system logs for suspicious activity related to chroot usage, especially attempts to create or modify device files within a chroot environment.
Monitor file system changes, particularly in critical system directories, for unauthorized modifications.
Analyze process execution logs for unusual processes running with elevated privileges.
Network traffic analysis for any unusual outbound connections originating from the compromised system.
Upgrade to a modern, supported operating system. Digital Ultrix is no longer supported and has known security vulnerabilities.
If upgrading is not possible, apply all available security patches and updates for Digital Ultrix.
Carefully review and secure the configuration of the chroot environment, ensuring proper access controls and resource restrictions.
Implement strong password policies and multi-factor authentication for all user accounts.
Regularly audit system logs and monitor for suspicious activity.
Implement a host-based intrusion detection system (HIDS) to detect malicious activity.