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.
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Overview
CAPEC-322 (TCP (ISN) Greatest Common Divisor Probe) is a detailed-level attack pattern catalogued by MITRE in the Common Attack Pattern Enumeration and Classification (CAPEC). It describes a recurring method attackers use to exploit software weaknesses.
What the attacker needs
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.
Resources required
- A tool capable of sending and receiving packets from a remote system.
Consequences
What a successful CAPEC-322 attack can achieve.
Read Data
Affects: Confidentiality
Bypass Protection Mechanism, Hide Activities
Affects: Confidentiality, Access Control, Authorization
Frequently asked questions
Common questions about CAPEC-322.
- What is CAPEC-322?
- 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.
- What weaknesses does CAPEC-322 target?
- CAPEC-322 exploits 1 CWE weakness, including CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor).
- How severe is CAPEC-322?
- MITRE rates CAPEC-322 as Low severity with medium likelihood of attack.
References
Attack-pattern data is sourced from the MITRE CAPEC catalog (v3.9). Weakness associations link to the corresponding CWE entries on RadicalNotion.AI.
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