CAPEC Definitions

    CAPEC Definitions / CAPEC-86

    CAPEC-86: XSS Through HTTP Headers

    An adversary exploits web applications that generate web content, such as links in a HTML page, based on unvalidated or improperly validated data submitted by other actors. XSS in HTTP Headers attacks target the HTTP headers which are hidden from most users and may not be validated by web applications.

    Severity:Very High
    Possibility:High

    Extended Description

    No Extended Description.

    Mitigations

    Design: Use browser technologies that do not allow client side scripting.

    Design: Utilize strict type, character, and encoding enforcement

    Design: Server side developers should not proxy content via XHR or other means, if a http proxy for remote content is setup on the server side, the client's browser has no way of discerning where the data is originating from.

    Implementation: Ensure all content that is delivered to client is sanitized against an acceptable content specification.

    Implementation: Perform input validation for all remote content.

    Implementation: Perform output validation for all remote content.

    Implementation: Disable scripting languages such as JavaScript in browser

    Implementation: Session tokens for specific host

    Implementation: Patching software. There are many attack vectors for XSS on the client side and the server side. Many vulnerabilities are fixed in service packs for browser, web servers, and plug in technologies, staying current on patch release that deal with XSS countermeasures mitigates this.

    Relationships with other CAPECs

    CAPEC-591: Reflected XSS

    CAPEC-588: DOM-Based XSS

    CAPEC-592: Stored XSS

    Prerequisites

    Target software must be a client that allows scripting communication from remote hosts.

    Related Weaknesses

    CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)