Source: cve@mitre.org
Vulnerability in DEC OpenVMS VAX 5.5-2 through 5.0, and OpenVMS AXP 1.0, allows local users to gain system privileges.
Critical vulnerability in legacy DEC OpenVMS systems allows local users to escalate privileges to the system level, potentially granting complete control of the affected server. This flaw, present in older versions of OpenVMS, poses a significant risk to organizations still operating these systems, enabling unauthorized access and data breaches.
Step 1: Local Access: An attacker must first gain local access to the OpenVMS system. This could be through a compromised user account, physical access, or another vulnerability that allows local shell access. Step 2: Exploit Trigger: The attacker executes a crafted exploit designed to leverage the vulnerability. The specific exploit varies depending on the underlying flaw, but it likely involves manipulating system calls, exploiting a buffer overflow, or triggering a race condition. Step 3: Privilege Escalation: The exploit successfully triggers the vulnerability, allowing the attacker to elevate their privileges from a standard user to a system-level account (e.g., SYSTEM). This grants the attacker complete control over the system. Step 4: System Compromise: With system-level privileges, the attacker can install backdoors, steal sensitive data, modify system configurations, and potentially compromise other systems on the network.
The vulnerability stems from a flaw in how OpenVMS handles user authentication and privilege escalation. The exact mechanism is not explicitly stated in the CVE description, but it's highly probable that it involves a privilege escalation vulnerability, possibly related to improper handling of user accounts, access control lists (ACLs), or system services. The root cause is likely a combination of factors, including inadequate input validation, insecure default configurations, and potential buffer overflows or race conditions within system utilities or privileged processes. The age of the system and the lack of modern security features exacerbate the risk.
Given the age of the vulnerability, it's unlikely to be directly associated with specific modern APTs. However, any threat actor targeting legacy systems would likely be interested in this vulnerability. The vulnerability is not listed on the CISA KEV (Known Exploited Vulnerabilities) catalog, likely due to the age of the affected systems and their limited presence in modern infrastructure.
Monitor system logs for suspicious activity, such as unauthorized privilege escalation attempts or unusual system calls.
Analyze process creation and termination events for any processes launched with elevated privileges by non-privileged users.
Review user account activity for any unexpected changes or logins.
Network monitoring for unusual traffic patterns originating from or destined to the OpenVMS system.
Implement file integrity monitoring to detect any unauthorized modifications to system files or binaries.
The most effective remediation is to migrate away from the affected OpenVMS versions to a more secure and supported operating system. This is the only truly effective solution.
If migration is not immediately feasible, apply all available security patches and updates for the OpenVMS version. However, patching may be limited or unavailable.
Implement strict access controls and least privilege principles. Limit user access to only the necessary resources and privileges.
Regularly audit user accounts and system configurations for any vulnerabilities or misconfigurations.
Implement strong password policies and multi-factor authentication (MFA) where possible. Note that MFA support may be limited on these legacy systems.
Isolate the OpenVMS system from the rest of the network to limit the impact of a potential compromise.
Consider using a host-based intrusion detection system (HIDS) to monitor for malicious activity.