CAPEC-88: 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.
- Likelihood of attack
- High
- Typical severity
- High
- Abstraction
- StandardA specific methodology or technique used in an attack.
Mechanism of attack: Inject Unexpected Items
Prerequisites
- User controllable input used as part of commands to the underlying operating system.
Skills required
- HighThe 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.
Consequences
- ConfidentialityIntegrityAvailability
Execute Unauthorized Commands
Run Arbitrary Code
- ConfidentialityAccess ControlAuthorization
Gain Privileges; Bypass Protection Mechanism
- Confidentiality
Read Data
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.