CAPEC Definitions

    CAPEC Definitions / CAPEC-146

    CAPEC-146: XML Schema Poisoning

    An adversary corrupts or modifies the content of XML schema information passed between a client and server for the purpose of undermining the security of the target. XML Schemas provide the structure and content definitions for XML documents. Schema poisoning is the ability to manipulate a schema either by replacing or modifying it to compromise the programs that process documents that use this schema.

    Severity:High
    Possibility:Low

    Extended Description

    No Extended Description.

    Mitigations

    Design: Protect the schema against unauthorized modification.

    Implementation: For applications that use a known schema, use a local copy or a known good repository instead of the schema reference supplied in the XML document. Additionally, ensure that the proper permissions are set on local files to avoid unauthorized modification.

    Implementation: For applications that leverage remote schemas, use the HTTPS protocol to prevent modification of traffic in transit and to avoid unauthorized modification.

    Relationships with other CAPECs

    CAPEC-271: Schema Poisoning

    Prerequisites

    Some level of access to modify the target schema.

    The schema used by the target application must be improperly secured against unauthorized modification and manipulation.

    Related Weaknesses

    CWE-15: External Control of System or Configuration Setting

    CWE-472: External Control of Assumed-Immutable Web Parameter