Source: cve@mitre.org
Vulnerability in NeXT 1.0a and 1.0 with publicly accessible printers allows local users to gain privileges via a combination of the npd program and weak directory permissions.
NeXTSTEP systems running NeXT 1.0a and 1.0 are vulnerable to a local privilege escalation. This vulnerability, stemming from insecure printer configuration and weak directory permissions, allows attackers to gain root access by exploiting the npd program.
Step 1: Identify Target System: The attacker identifies a NeXTSTEP system running NeXT 1.0a or 1.0 with publicly accessible printers.
Step 2: Locate Printer Configuration: The attacker identifies the location of printer configuration files and print queues, often within world-writable directories.
Step 3: Craft Malicious Payload: The attacker crafts a malicious payload, such as a shell script or a program designed to gain root privileges.
Step 4: Inject Payload: The attacker injects the malicious payload into the printer configuration or print queue, potentially by submitting a specially crafted print job or modifying configuration files.
Step 5: Trigger Execution: The npd program, running with elevated privileges, processes the malicious payload, leading to the execution of the attacker's code.
Step 6: Privilege Escalation: The attacker's code executes with root privileges, granting the attacker full control over the system.
The root cause lies in the combination of two factors: the npd (NeXT Print Daemon) program's potential for misuse and the insecure default permissions on printer-related directories. Specifically, the npd program, when configured with publicly accessible printers, would often run with elevated privileges. Attackers could leverage this by manipulating the print queue or printer configuration files. The weak directory permissions, such as world-writable directories used by npd, allowed attackers to overwrite or inject malicious files. This could lead to arbitrary code execution with the privileges of the npd process, ultimately granting the attacker root access. The lack of proper input validation and access control mechanisms within npd exacerbated the issue, making it susceptible to exploitation.
Due to the age of the vulnerability and the rarity of the affected systems, there is no specific APT or malware directly associated with this CVE. This vulnerability is not listed in the CISA KEV catalog.
Monitor system logs for unusual activity related to the npd program, such as unexpected file modifications or process executions.
Analyze print queue logs for suspicious print jobs or commands.
Review file system permissions on printer-related directories to identify any world-writable or overly permissive settings.
Network traffic analysis for print-related protocols (e.g., LPD) to detect potentially malicious print jobs.
Isolate and decommission affected systems. Given the age of the systems, the best remediation is to remove them from the network.
If system cannot be removed, restrict access to printers. Ensure printers are not publicly accessible and require authentication.
Review and harden file system permissions. Ensure that printer-related directories are not world-writable and have appropriate access controls.
Monitor system logs and network traffic for suspicious activity.
Implement a robust patch management strategy to address any future vulnerabilities.