CAPEC Definitions

    CAPEC Definitions / CAPEC-322

    CAPEC-322: TCP (ISN) Greatest Common Divisor Probe

    This OS fingerprinting probe sends a number of TCP SYN packets to an open port of a remote machine. The Initial Sequence Number (ISN) in each of the SYN/ACK response packets is analyzed to determine the smallest number that the target host uses when incrementing sequence numbers. This information can be useful for identifying an operating system because particular operating systems and versions increment sequence numbers using different values. The result of the analysis is then compared against a database of OS behaviors to determine the OS type and/or version.

    Severity:Low
    Possibility:Medium

    Extended Description

    No Extended Description.

    Mitigations

    No Mitigations found.

    Relationships with other CAPECs

    CAPEC-312: Active OS Fingerprinting

    Prerequisites

    The ability to monitor and interact with network communications.Access to at least one host, and the privileges to interface with the network interface card.

    Related Weaknesses

    CWE-200: Exposure of Sensitive Information to an Unauthorized Actor