Source: cve@mitre.org
Vulnerability in /usr/bin/mail in DEC ULTRIX before 4.2 allows local users to gain privileges.
Local privilege escalation is possible on vulnerable DEC ULTRIX systems due to a flaw in the /usr/bin/mail utility. Successful exploitation allows attackers to gain root access, potentially compromising the entire system and leading to data breaches or system control.
Step 1: Local Access: The attacker must first have local access to the vulnerable ULTRIX system, typically through a compromised user account or physical access.
Step 2: Crafting the Malicious Mail: The attacker crafts a specially formatted mail message. This message contains a payload designed to exploit the vulnerability in /usr/bin/mail.
Step 3: Sending the Mail: The attacker sends the crafted mail message to themselves or another local user, triggering the mail program to process it.
Step 4: Vulnerability Trigger: When /usr/bin/mail processes the malicious message, the vulnerability is triggered. The crafted input overwrites memory, leading to arbitrary code execution.
Step 5: Privilege Escalation: The injected code executes with the privileges of the /usr/bin/mail program, which typically runs with elevated privileges (e.g., root) during certain operations. This allows the attacker to gain root access.
The vulnerability stems from a flaw in how the /usr/bin/mail utility handles user input, specifically when processing mail messages. The exact nature of the vulnerability is likely a format string vulnerability or a buffer overflow within the mail program's parsing logic. This allows a local user to craft a malicious mail message that, when processed by the vulnerable mail program, overwrites critical memory locations, such as the stack or heap, to execute arbitrary code with elevated privileges. The vulnerability likely resides in the handling of user-supplied data within the mail message headers or body, where insufficient input validation or sanitization allows for the injection of malicious code or control characters.
Due to the age of the vulnerability and the target system, it is unlikely to be directly associated with specific APT groups. However, any attacker with access to a vulnerable system could leverage this vulnerability. This CVE is not listed in the CISA KEV catalog due to its age and the rarity of the affected systems.
Monitor system logs for unusual activity related to the /usr/bin/mail program, such as unexpected crashes or errors.
Analyze mail message content for suspicious patterns or payloads, especially in headers or body content.
Examine system process activity for processes spawned by /usr/bin/mail that exhibit unusual behavior or privileges.
Implement file integrity monitoring to detect any unauthorized modifications to the /usr/bin/mail executable or related libraries.
Network monitoring for unusual traffic patterns originating from the affected system, indicating potential command and control activity after exploitation.
The primary remediation is to isolate or decommission the affected ULTRIX systems. Due to the age of the system, patching is unlikely.
If decommissioning is not possible, implement strict access controls to limit local user access.
Monitor system logs and network traffic for suspicious activity.
Implement a host-based intrusion detection system (HIDS) to detect malicious activity.
Consider using a network intrusion detection system (NIDS) to monitor for suspicious network traffic.