COMMON ATTACK PATTERN ENUMERATION AND CLASSIFICATIONLive MITRE record

CAPEC-65

Sniff Application Code

An adversary passively sniffs network communications and captures application code bound for an authorized client. Once obtained, they can use it as-is, or through reverse-engineering glean sensitive information or exploit the trust relationship between the client and server. Such code may belong to a dynamic update to the client, a patch being applied to a client component or any such interaction where the client is authorized to communicate with the server.

Abstraction

Detailed

Typical severity

High

Likelihood of attack

Low

Understand the attack

What is this attack pattern?

An adversary passively sniffs network communications and captures application code bound for an authorized client. Once obtained, they can use it as-is, or through reverse-engineering glean sensitive information or exploit the trust relationship between the client and server. Such code may belong to a dynamic update to the client, a patch being applied to a client component or any such interaction where the client is authorized to communicate with the server.

Execution flow

How does the attack proceed, step by step?

1

Explore

Set up a sniffer

The adversary sets up a sniffer in the path between the server and the client and watches the traffic.

Techniques used

  • The adversary sets up a sniffer in the path between the server and the client.
2

Exploit

Capturing Application Code Bound During Patching

Techniques used

  • adversary loads the sniffer to capture the application code bound during a dynamic update.
  • The adversary proceeds to reverse engineer the captured code.

Requirements

What does the attack require?

Prerequisites

  • The attacker must have the ability to place themself in the communication path between the client and server.
  • The targeted application must receive some application code from the server; for example, dynamic updates, patches, applets or scripts.
  • The attacker must be able to employ a sniffer on the network without being detected.

Skills required

  • Medium: The attacker needs to setup a sniffer for a sufficient period of time so as to capture meaningful quantities of code. The presence of the sniffer should not be detected on the network. Also if the attacker plans to employ an adversary-in-the-middle attack ( CAPEC-94 ), the client or server must not realize this. Finally, the attacker needs to regenerate source code from binary code if the need be.

Resources required

  • The Attacker needs the ability to capture communications between the client being updated and the server providing the update. In the case that encryption obscures client/server communication the attacker will either need to lift key material from the client.

Impact

What does a successful attack lead to?

Read Data

Affected scopes: Confidentiality

Gain Privileges

Affected scopes: Confidentiality, Access Control, Authorization

Defence

How is it prevented and mitigated?

1
Design: Encrypt all communication between the client and server.
2
Implementation: Use SSL, SSH, SCP.
3
Operation: Use "ifconfig/ipconfig" or other tools to detect the sniffer installed in the network.

Real world

MITRE example instances

Example instance 1Detail
Attacker receives notification that the computer/OS/application has an available update, loads a network sniffing tool, and extracts update data from subsequent communication. The attacker then proceeds to reverse engineer the captured stream to gain sensitive information, such as encryption keys, validation algorithms, applications patches, etc..
Example instance 2Detail
Plain code, such as applets or JavaScript, is also part of the executing application. If such code is transmitted unprotected, the attacker can capture the code and possibly reverse engineer it to gain sensitive information, such as encryption keys, validation algorithms and such.