Detailed attack pattern

Stable

CAPEC-320: TCP Timestamp Probe

This OS fingerprinting probe examines the remote server's implementation of TCP timestamps. Not all operating systems implement timestamps within the TCP header, but when timestamps are used then this provides the attacker with a means to guess the operating system of the target. The attacker begins by probing any active TCP service in order to get response which contains a TCP timestamp. Different Operating systems update the timestamp value using different intervals. This type of analysis is most accurate when multiple timestamp responses are received and then analyzed. TCP timestamps can be found in the TCP Options field of the TCP header.

Last updated June 1, 2026

Low

Typical severity

Per MITRE

Medium

Likelihood of attack

Per MITRE

1

Related weaknesses

CWEs this targets

Detailed

Abstraction

MITRE classification

Overview

CAPEC-320 (TCP Timestamp 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.

How the attack works

The phases an attacker typically follows to carry out this attack.

Step 1
Explore
[Determine if timestamps are present.] The adversary sends a probe packet to the remote host to identify if timestamps are present.
Step 2
Experiment
[Record and analyze timestamp values.] If the remote host is using timestamp, obtain several timestamps, analyze them and compare them to known values.
- The adversary sends several requests and records the timestamp values.
- The adversary analyzes the timestamp values and determines an average increments per second in the timestamps for the target.
- The adversary compares this result to a database of known TCP timestamp increments for a possible match.

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.The target OS must support the TCP timestamp option in order to obtain a fingerprint.

Resources required

Any type of active probing that involves non-standard packet headers requires the use of raw sockets, which is not available on particular operating systems (Microsoft Windows XP SP 2, for example). Raw socket manipulation on Unix/Linux requires root privileges. A tool capable of sending and receiving packets from a remote system.

Consequences

What a successful CAPEC-320 attack can achieve.

Read Data

Affects: Confidentiality

Bypass Protection Mechanism

Affects: Confidentiality, Access Control, Authorization

Frequently asked questions

Common questions about CAPEC-320.

What is CAPEC-320?

This OS fingerprinting probe examines the remote server's implementation of TCP timestamps. Not all operating systems implement timestamps within the TCP header, but when timestamps are used then this provides the attacker with a means to guess the operating system of the target. The attacker begins by probing any active TCP service in order to get response which contains a TCP timestamp. Different Operating systems update the timestamp value using different intervals. This type of analysis is most accurate when multiple timestamp responses are received and then analyzed. TCP timestamps can be found in the TCP Options field of the TCP header.

How does a TCP Timestamp Probe attack work?

It typically unfolds over 2 phases. It begins with: [Determine if timestamps are present.] The adversary sends a probe packet to the remote host to identify if timestamps are present.

What weaknesses does CAPEC-320 target?

CAPEC-320 exploits 1 CWE weakness, including CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor).

How severe is CAPEC-320?

MITRE rates CAPEC-320 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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Overview

Overview

How the attack works

What the attacker needs

Prerequisites

Resources required

Consequences

Related weaknesses

Related attack patterns

Parent

Frequently asked questions

What is CAPEC-320?

How does a TCP Timestamp Probe attack work?

What weaknesses does CAPEC-320 target?

How severe is CAPEC-320?

References

Defend against CAPEC-320