CAPEC-88

Standard Abstraction Level
Meta — Very abstract, high-level category
Standard — Specific enough to understand
Detailed — Tied to specific technique Draft MITRE CAPEC Status
Stable — Fully reviewed and complete
Draft — Under development
Incomplete — Partially defined
Deprecated — No longer recommended
Obsolete — Replaced by another CAPEC Likelihood: High Severity: High
OS Command Injection

Description

In this type of an attack, an adversary injects operating system commands into existing application functions. An application that uses untrusted input to build command strings is vulnerable. An adversary can leverage OS command injection in an application to elevate privileges, execute arbitrary commands and compromise the underlying operating system.

Prerequisites

User controllable input used as part of commands to the underlying operating system.

Mitigations

Use language APIs rather than relying on passing data to the operating system shell or command line. Doing so ensures that the available protection mechanisms in the language are intact and applicable.

Filter all incoming data to escape or remove characters or strings that can be potentially misinterpreted as operating system or shell commands

All application processes should be run with the minimal privileges required. Also, processes must shed privileges as soon as they no longer require them.

Skills Required

[High] The attacker needs to have knowledge of not only the application to exploit but also the exact nature of commands that pertain to the target operating system. This may involve, though not always, knowledge of specific assembly commands for the platform.