CAPEC Details
Name ICMP IP Total Length Field Probe
Likelyhood of attack Typical severity
Medium Low
Summary An adversary sends a UDP packet to a closed port on the target machine to solicit an IP Header's total length field value within the echoed 'Port Unreachable" error message. This type of behavior is useful for building a signature-base of operating system responses, particularly when error messages contain other types of information that is useful identifying specific operating system responses.
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.
Solutions
Related Weaknesses
CWE ID Description
CWE-204 Observable Response Discrepancy
Related CAPECS
CAPEC ID Description
CAPEC-312 An adversary engages in activity to detect the operating system or firmware version of a remote target by interrogating a device, server, or platform with a probe designed to solicit behavior that will reveal information about the operating systems or firmware in the environment. Operating System detection is possible because implementations of common protocols (Such as IP or TCP) differ in distinct ways. While the implementation differences are not sufficient to 'break' compatibility with the protocol the differences are detectable because the target will respond in unique ways to specific probing activity that breaks the semantic or logical rules of packet construction for a protocol. Different operating systems will have a unique response to the anomalous input, providing the basis to fingerprint the OS behavior. This type of OS fingerprinting can distinguish between operating system types and versions.