An adversary targets the communication between two components (typically client and server), in order to alter or obtain data from transactions. A general approach entails the adversary placing themself within the communication channel between the two components.

Execution Flow

1) Explore

[Determine Communication Mechanism] The adversary determines the nature and mechanism of communication between two components, looking for opportunities to exploit.

Technique

• Perform a sniffing attack and observe communication to determine a communication protocol.
• Look for application documentation that might describe a communication mechanism used by a target.

2) Experiment

[Position In Between Targets] The adversary inserts themself into the communication channel initially acting as a routing proxy between the two targeted components.

Technique

• Install spyware on a client that will intercept outgoing packets and route them to their destination as well as route incoming packets back to the client.
• Exploit a weakness in an encrypted communication mechanism to gain access to traffic. Look for outdated mechanisms such as SSL.

3) Exploit

[Use Intercepted Data Maliciously] The adversary observes, filters, or alters passed data of its choosing to gain access to sensitive information or to manipulate the actions of the two target components for their own purposes.

Technique

• Prevent some messages from reaching their destination, causing a denial of service.

Prerequisites

There are two components communicating with each other.
An attacker is able to identify the nature and mechanism of communication between the two target components.
An attacker can eavesdrop on the communication between the target components.
Strong mutual authentication is not used between the two target components yielding opportunity for attacker interposition.
The communication occurs in clear (not encrypted) or with insufficient and spoofable encryption.

Skills Required

This attack can get sophisticated since the attack may use cryptography.

Mitigations

Ensure Public Keys are signed by a Certificate Authority
Encrypt communications using cryptography (e.g., SSL/TLS)
Use Strong mutual authentication to always fully authenticate both ends of any communications channel.
Exchange public keys using a secure channel

Related Weaknesses

References

REF-553

Computer Security: Art and Science
M. Bishop.

REF-633

Man-in-the-middle attack
https://owasp.org/www-community/attacks/Man-in-the-middle_attack

REF-634

What is a man-in-the-middle attack?
Kyle Chivers.
https://us.norton.com/internetsecurity-wifi-what-is-a-man-in-the-middle-attack.html

REF-635

Man in the middle (MITM) attack
https://www.imperva.com/learn/application-security/man-in-the-middle-attack-mitm/

REF-636

Settling the score: taking down the Equifax mobile application
Jerry Decime.
https://www.linkedin.com/pulse/settling-score-taking-down-equifax-mobile-application-jerry-decime/

Submission

Modifications