CAPEC Definitions

    CAPEC Definitions / CAPEC-4

    CAPEC-4: Using Alternative IP Address Encodings

    This attack relies on the adversary using unexpected formats for representing IP addresses. Networked applications may expect network location information in a specific format, such as fully qualified domains names (FQDNs), URL, IP address, or IP Address ranges. If the location information is not validated against a variety of different possible encodings and formats, the adversary can use an alternate format to bypass application access control.

    Severity:High
    Possibility:Medium

    Extended Description

    No Extended Description.

    Mitigations

    Design: Default deny access control policies

    Design: Input validation routines should check and enforce both input data types and content against a positive specification. In regards to IP addresses, this should include the authorized manner for the application to represent IP addresses and not accept user specified IP addresses and IP address formats (such as ranges)

    Implementation: Perform input validation for all remote content.

    Relationships with other CAPECs

    CAPEC-267: Leverage Alternate Encoding

    Prerequisites

    The target software must fail to anticipate all of the possible valid encodings of an IP/web address.

    The adversary must have the ability to communicate with the server.

    Related Weaknesses

    CWE-291: Reliance on IP Address for Authentication

    CWE-173: Improper Handling of Alternate Encoding