Source: cve@mitre.org
The default configuration for UUCP in AIX before 3.2 allows local users to gain root privileges.
AIX systems running UUCP with default configurations are vulnerable to a local privilege escalation, allowing attackers to gain root access. This vulnerability, dating back to AIX 3.2, stems from insecure default settings within the UUCP configuration, enabling unauthorized access and control of the system. Successful exploitation grants complete control of the compromised server.
Step 1: Identify Vulnerable System: The attacker identifies an AIX system running a vulnerable version of AIX (pre-3.2) with UUCP enabled and using the default configuration.
Step 2: Local Access: The attacker gains local access to the system, potentially through a compromised user account or physical access.
Step 3: Exploit Execution: The attacker crafts a malicious UUCP command or utilizes a known exploit against the insecure UUCP configuration. This could involve manipulating UUCP configuration files or abusing the way UUCP handles file transfers or command execution.
Step 4: Privilege Escalation: The crafted exploit leverages the insecure UUCP configuration to execute commands with root privileges. This could involve writing to privileged files, executing commands as root, or modifying system settings.
Step 5: System Compromise: The attacker gains complete control of the system, including the ability to install backdoors, steal data, and disrupt operations.
The vulnerability lies in the default configuration of UUCP (Unix-to-Unix Copy Protocol) on AIX systems prior to version 3.2. Specifically, the configuration likely lacked proper access controls for UUCP commands and files. This allowed local users to execute UUCP commands with elevated privileges, potentially through a command injection or path traversal vulnerability. The root cause is the insecure default settings that grant excessive permissions to the UUCP process, enabling unauthorized modification of system files or execution of privileged commands. The specific flaw is likely related to how UUCP handles incoming requests and processes data, failing to properly validate user input or restrict access to sensitive resources. This could involve a trust relationship between UUCP and the operating system that is exploited.
Due to the age of this vulnerability, it's unlikely to be directly associated with specific APT groups in recent reports. However, any threat actor targeting legacy systems would likely be aware of and exploit this vulnerability. This vulnerability is not listed on the CISA KEV catalog due to its age and the fact that it's unlikely to be a widespread threat in modern environments. However, it's a reminder of the importance of patching and maintaining up-to-date systems.
Monitor system logs (e.g., /var/adm/messages, syslog) for suspicious UUCP activity, such as unexpected command executions or file modifications.
Analyze UUCP configuration files (e.g., /usr/lib/uucp/Devices, /usr/lib/uucp/Permissions) for insecure settings, such as overly permissive access controls.
Monitor network traffic for UUCP-related protocols (e.g., uucp, uucpd) and analyze for suspicious data transfers or command executions.
Implement file integrity monitoring to detect unauthorized changes to critical system files.
Use a vulnerability scanner to identify systems running vulnerable versions of AIX and UUCP.
Upgrade to a supported version of AIX that addresses the vulnerability. This is the most effective solution.
If upgrading is not possible, disable UUCP if it is not required. This eliminates the attack surface.
If UUCP must be used, review and harden the UUCP configuration. Specifically, restrict access to UUCP commands and files, and implement strong authentication mechanisms.
Apply security patches and updates provided by IBM for the affected AIX versions.
Implement a strong password policy and enforce multi-factor authentication for all user accounts.
Regularly audit system configurations and access controls to ensure they are secure.