WEBSEC D. Ross
Internet-Draft Microsoft
Intended status: Standards Track T. Gondrom
Expires: January 7, 2013 July 6, 2012
HTTP Header Frame Options
draft-ietf-websec-frame-options-00
Abstract
To improve the protection of web applications against Clickjacking
this standards defines a http response header that declares a policy
communicated from a host to the client browser whether the
transmitted content MUST NOT be displayed in frames of other pages
from different origins which are allowed to frame the content.
Status of this Memo
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This Internet-Draft will expire on January 7, 2013.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . . 3
2. Frame-Options Header . . . . . . . . . . . . . . . . . . . . . 3
2.1. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Backus-Naur Form (BNF) . . . . . . . . . . . . . . . . . . 4
2.3. Design Issues . . . . . . . . . . . . . . . . . . . . . . . 5
2.3.1. Enable HTML content from other domains . . . . . . . . 5
2.3.2. Browser Behaviour and Processing . . . . . . . . . . . 5
2.4. Examples of Frame-Options Headers . . . . . . . . . . . . . 6
2.4.1. Example scenario for the ALLOW-FROM parameter . . . . . 6
3. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
4.1. Registration Template . . . . . . . . . . . . . . . . . . . 7
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 7
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.1. Normative References . . . . . . . . . . . . . . . . . . . 7
6.2. Informative References . . . . . . . . . . . . . . . . . . 7
Appendix A. Description of a Clickjacking attack . . . . . . . . . 8
A.1. Shop . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
A.2. Confirm Purchase Page . . . . . . . . . . . . . . . . . . . 9
A.3. Flash Configuration . . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 9
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1. Introduction
In 2009 and 2010 many browser vendors introduced the use of a non-
standard http header RFC 2616 [RFC2616] "X-Frame-Options" to protect
against Clickjacking [Clickjacking]. This standard is to replace the
non-standard header.
Existing anti-ClickJacking measures, e.g. Frame-breaking Javascript,
have weaknesses so that their protection can be circumvented as a
study [FRAME-BUSTING] demonstrated.
Short of configuring the browser to disable frames and script
entirely, which massively impairs browser utility, browser users are
vulnerable to this type of attack.
"Frame-Options" allows a secure web page from host B to declare that
its content (for example a button, links, text, etc.) must not be
displayed in a frame of another page (e.g. from host A). In
principle this is done by a policy declared in the HTTP header and
obeyed by conform browser implementations.
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
2. Frame-Options Header
The Frame-Options HTTP response header indicates a policy whether a
browser MUST NOT allow to render a page in a or