COMMON ATTACK PATTERN ENUMERATION AND CLASSIFICATIONLive MITRE record

CAPEC-6

Argument Injection

An attacker changes the behavior or state of a targeted application through injecting data or command syntax through the targets use of non-validated and non-filtered arguments of exposed services or methods.

Abstraction

Standard

Typical severity

High

Likelihood of attack

High

Understand the attack

What is this attack pattern?

An attacker changes the behavior or state of a targeted application through injecting data or command syntax through the targets use of non-validated and non-filtered arguments of exposed services or methods.

Execution flow

How does the attack proceed, step by step?

1

Explore

Discovery of potential injection vectors

Using an automated tool or manual discovery, the attacker identifies services or methods with arguments that could potentially be used as injection vectors (OS, API, SQL procedures, etc.).

Techniques used

  • Manually cover the application and record the possible places where arguments could be passed into external systems.
  • Use a spider, for web applications, to create a list of URLs and associated inputs.
2

Experiment

1. Attempt variations on argument content

Possibly using an automated tool, the attacker will perform injection variations of the arguments.

Techniques used

  • Use a very large list of probe strings in order to detect if there is a positive result, and, what type of system has been targeted (if obscure).
  • Use a proxy tool to record results, error messages and/or log if accessible.
3

Exploit

Abuse of the application

The attacker injects specific syntax into a particular argument in order to generate a specific malicious effect in the targeted application.

Techniques used

  • Manually inject specific payload into targeted argument.

Requirements

What does the attack require?

Prerequisites

  • Target software fails to strip all user-supplied input of any content that could cause the shell to perform unexpected actions.
  • Software must allow for unvalidated or unfiltered input to be executed on operating system shell, and, optionally, the system configuration must allow for output to be sent back to client.

Skills required

  • Medium: The attacker has to identify injection vector, identify the operating system-specific commands, and optionally collect the output.

Resources required

  • Ability to communicate synchronously or asynchronously with server. Optionally, ability to capture output directly through synchronous communication or other method such as FTP.

Impact

What does a successful attack lead to?

Gain Privileges

Affected scopes: Confidentiality, Access Control, Authorization

Modify Data

Affected scopes: Integrity

Read Data

Affected scopes: Confidentiality

Defence

How is it prevented and mitigated?

1
Design: Do not program input values directly on command shell, instead treat user input as guilty until proven innocent. Build a function that takes user input and converts it to applications specific types and values, stripping or filtering out all unauthorized commands and characters in the process.
2
Design: Limit program privileges, so if metacharacters or other methods circumvent program input validation routines and shell access is attained then it is not running under a privileged account. chroot jails create a sandbox for the application to execute in, making it more difficult for an attacker to elevate privilege even in the case that a compromise has occurred.
3
Implementation: Implement an audit log that is written to a separate host, in the event of a compromise the audit log may be able to provide evidence and details of the compromise.

Real world

MITRE example instances

Example instance 1Detail
A recent example instance of argument injection occurred against Java Web Start technology, which eases the client side deployment for Java programs. The JNLP files that are used to describe the properties for the program. The client side Java runtime used the arguments in the property setting to define execution parameters, but if the attacker appends commands to an otherwise legitimate property file, then these commands are sent to the client command shell. [ REF-482 ]
CAPEC-6: Argument Injection — DayBreach Saldırı Sözlüğü · DayBreach