idnits 2.17.1 draft-ietf-websec-x-frame-options-00.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (July 3, 2012) is 4314 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- == Missing Reference: 'TBD' is mentioned on line 167, but not defined == Unused Reference: 'CLICK-DEFENSE-BLOG' is defined on line 279, but no explicit reference was found in the text -- Obsolete informational reference (is this intentional?): RFC 822 (Obsoleted by RFC 2822) -- Obsolete informational reference (is this intentional?): RFC 2616 (Obsoleted by RFC 7230, RFC 7231, RFC 7232, RFC 7233, RFC 7234, RFC 7235) Summary: 0 errors (**), 0 flaws (~~), 3 warnings (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 WEBSEC D. Ross 3 Internet-Draft Microsoft 4 Intended status: Informational T. Gondrom 5 Expires: January 4, 2013 July 3, 2012 7 HTTP Header X-Frame-Options 8 draft-ietf-websec-x-frame-options-00 10 Abstract 12 To improve the protection of web applications against Clickjacking 13 this standards defines a http response header that declares a policy 14 communicated from a host to the client browser whether the 15 transmitted content MUST NOT be displayed in frames of other pages 16 from different origins which are allowed to frame the content. This 17 drafts serves to document the existing use and specification of 18 X-Frame-Options. 20 Status of this Memo 22 This Internet-Draft is submitted in full conformance with the 23 provisions of BCP 78 and BCP 79. 25 Internet-Drafts are working documents of the Internet Engineering 26 Task Force (IETF). Note that other groups may also distribute 27 working documents as Internet-Drafts. The list of current Internet- 28 Drafts is at http://datatracker.ietf.org/drafts/current/. 30 Internet-Drafts are draft documents valid for a maximum of six months 31 and may be updated, replaced, or obsoleted by other documents at any 32 time. It is inappropriate to use Internet-Drafts as reference 33 material or to cite them other than as "work in progress." 35 This Internet-Draft will expire on January 4, 2013. 37 Copyright Notice 39 Copyright (c) 2012 IETF Trust and the persons identified as the 40 document authors. All rights reserved. 42 This document is subject to BCP 78 and the IETF Trust's Legal 43 Provisions Relating to IETF Documents 44 (http://trustee.ietf.org/license-info) in effect on the date of 45 publication of this document. Please review these documents 46 carefully, as they describe your rights and restrictions with respect 47 to this document. Code Components extracted from this document must 48 include Simplified BSD License text as described in Section 4.e of 49 the Trust Legal Provisions and are provided without warranty as 50 described in the Simplified BSD License. 52 Table of Contents 54 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 55 1.1. Requirements Language . . . . . . . . . . . . . . . . . . . 3 56 2. X-Frame-Options Header . . . . . . . . . . . . . . . . . . . . 3 57 2.1. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . 3 58 2.2. Backus-Naur Form (BNF) . . . . . . . . . . . . . . . . . . 4 59 2.3. Design Issues . . . . . . . . . . . . . . . . . . . . . . . 5 60 2.3.1. Enable HTML content from other domains . . . . . . . . 5 61 2.3.2. Browser Behaviour and Processing . . . . . . . . . . . 5 62 2.4. Examples of X-Frame-Options Headers . . . . . . . . . . . . 5 63 2.4.1. Example scenario for the ALLOW-FROM parameter . . . . . 6 64 3. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6 65 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 66 4.1. Registration Template . . . . . . . . . . . . . . . . . . . 7 67 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 7 68 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 69 6.1. Normative References . . . . . . . . . . . . . . . . . . . 7 70 6.2. Informative References . . . . . . . . . . . . . . . . . . 7 71 Appendix A. Description of a Clickjacking attack . . . . . . . . . 8 72 A.1. Shop . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 73 A.2. Confirm Purchase Page . . . . . . . . . . . . . . . . . . . 8 74 A.3. Flash Configuration . . . . . . . . . . . . . . . . . . . . 9 75 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 9 77 1. Introduction 79 In 2009 and 2010 many browser vendors introduced the use of a non- 80 standard http header RFC 2616 [RFC2616] "X-Frame-Options" to protect 81 against Clickjacking [Clickjacking]. This draft is to document the 82 current use of X-Frame-Options header and shall in the future be 83 replaced by the Frame-Options (CSRF) [FRAME-OPTIONS] standard. 85 Existing anti-ClickJacking measures, e.g. Frame-breaking Javascript, 86 have weaknesses so that their protection can be circumvented as a 87 study [FRAME-BUSTING] demonstrated. 89 Short of configuring the browser to disable frames and script 90 entirely, which massively impairs browser utility, browser users are 91 vulnerable to this type of attack. 93 The "X-Frame-Options" allows a secure web page from host B to declare 94 that its content (for example a button, links, text, etc.) must not 95 be displayed in a frame of another page (e.g. from host A). In 96 principle this is done by a policy declared in the HTTP header and 97 obeyed by conform browser implementations. 99 1.1. Requirements Language 101 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 102 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 103 document are to be interpreted as described in RFC 2119 [RFC2119]. 105 2. X-Frame-Options Header 107 The X-Frame-Options HTTP response header indicates a policy whether a 108 browser MUST NOT allow to render a page in a or