CAPEC Details
Name ICMP Error Message Quoting Probe
Likelyhood of attack Typical severity
Medium Low
Summary An adversary uses a technique to generate an ICMP Error message (Port Unreachable, Destination Unreachable, Redirect, Source Quench, Time Exceeded, Parameter Problem) from a target and then analyze the amount of data returned or "Quoted" from the originating request that generated the ICMP error message. For this purpose "Port Unreachable" error messages are often used, as generating them requires the attacker to send a UDP datagram to a closed port on the target. The goal of this analysis to make inferences about the type of operating system or firmware that sent the error message in reply. This is useful for identifying unique characteristics of operating systems because the RFC-1122 expected behavior reads: "Every ICMP error message includes the Internet header and at least the first 8 data octets of the datagram that triggered the error; more than 8 octets MAY be sent [...]." This contrasts with RFC-792 expected behavior, which limited the quoted text to 64 bits (8 octets). Given the latitude in the specification the resulting RFC-1122 stack implementations often respond with a high degree of variability in the amount of data quoted in the error message because "older" or "legacy" stacks may comply with the RFC-792 specification, while other stacks may choose a longer format in accordance with RFC-1122. As a general rule most operating systems or firmware will quote the first 8 bytes of the datagram triggering the error, but some IP stacks will quote more than the first 8 bytes of data.
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 ID Description
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
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.