CAPEC Definitions

    CAPEC Definitions / CAPEC-6

    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.

    Severity:High
    Possibility:High

    Extended Description

    No Extended Description.

    Mitigations

    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.

    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.

    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.

    Relationships with other CAPECs

    CAPEC-137: Parameter Injection

    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.

    Related Weaknesses

    CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

    CWE-146: Improper Neutralization of Expression/Command Delimiters

    CWE-184: Incomplete List of Disallowed Inputs

    CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

    CWE-185: Incorrect Regular Expression

    CWE-697: Incorrect Comparison