Finger Daemon Detection Scanner

The Finger Daemon is a program running on networked computers to disclose information about users logged into the system. It's primarily used by system administrators and technicians to gain information about users on a network or system for management purposes. Its primary function is executed over TCP and it commonly listens on port 79, providing user and status information to clients making queries. Originally developed for UNIX-like systems, it enables the display of certain user and host-related information that can aid in system management. In today’s network environments, though useful, it is often considered obsolete due to potential security vulnerabilities inherent in its operation. Despite its obsolescence, the Finger Daemon remains a part of internet history and in limited use for specific legacy purposes.

Technology detection for the Finger Daemon centers around determining the service's presence, which could potentially reveal sensitive information about system users. The scanner identifies active Finger Daemon services on assets through fingerprinting techniques. Port 79 is targeted during scans as it is the default listening port for the Finger Daemon. If an active Finger Daemon is discovered, it indicates possible exposure of user information and network configuration to unauthorized individuals. Recognizing the active daemon can help stakeholders assess and mitigate potential risks associated with unnecessary information exposure. Detection mechanisms rely on specific recognizable patterns in network traffic that signify Finger Daemon operations.

From a technical standpoint, the Finger Daemon is susceptible to information disclosure due to its tendency to share non-essential user details. The vulnerable endpoint listens on TCP port 79 and can be queried remotely to retrieve user data. The parameters involved in interacting with this service include user-specific terminal data, system load, and activity report concerning a remote host. To detect the Finger Daemon, scanners look for specific textual responses like "User", "Action", and "Node" that confirm the presence of the service. Misconfigured or outdated services can lead to significant network exposure, underlining the importance of detecting such services.

When the Finger Daemon is exploited, unauthorized users might receive private user and system status data. Such data could reveal sensitive information about user habits, terminal activities, and potential vulnerabilities within the host environment. The exposure encompasses risks of spear-phishing attacks where user data may act as a starting point for social engineering. Continued operation of the Finger Daemon in accessible network situations is seen as a potential vulnerability point that can be exploited if not correctly secured or deprecated. Malicious actors with access to this information can leverage it to map network topology or gather intelligence for heightened attack vectors.

REFERENCES

• https://www.shodan.io/search?query=port:79