OAuth 2.0 Security Best Current Practice
draft-ietf-oauth-security-topics-15

Document Type Active Internet-Draft (oauth WG)
Last updated 2020-04-05
Replaces draft-lodderstedt-oauth-security-topics
Stream IETF
Intended RFC status Best Current Practice
Formats plain text html xml pdf htmlized (tools) htmlized bibtex
Stream WG state WG Document
Document shepherd Hannes Tschofenig
IESG IESG state I-D Exists
Consensus Boilerplate Yes
Telechat date
Responsible AD (None)
Send notices to Hannes Tschofenig <hannes.tschofenig@arm.com>
Web Authorization Protocol                                T. Lodderstedt
Internet-Draft                                                   yes.com
Intended status: Best Current Practice                        J. Bradley
Expires: 7 October 2020                                           Yubico
                                                             A. Labunets
                                                                        
                                                                 D. Fett
                                                                 yes.com
                                                            5 April 2020

                OAuth 2.0 Security Best Current Practice
                  draft-ietf-oauth-security-topics-15

Abstract

   This document describes best current security practice for OAuth 2.0.
   It updates and extends the OAuth 2.0 Security Threat Model to
   incorporate practical experiences gathered since OAuth 2.0 was
   published and covers new threats relevant due to the broader
   application of OAuth 2.0.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 7 October 2020.

Copyright Notice

   Copyright (c) 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights

Lodderstedt, et al.      Expires 7 October 2020                 [Page 1]
Internet-Draft            oauth-security-topics               April 2020

   and restrictions with respect to this document.  Code Components
   extracted from this document must include Simplified BSD License text
   as described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Structure . . . . . . . . . . . . . . . . . . . . . . . .   4
     1.2.  Conventions and Terminology . . . . . . . . . . . . . . .   4
   2.  Recommendations . . . . . . . . . . . . . . . . . . . . . . .   5
     2.1.  Protecting Redirect-Based Flows . . . . . . . . . . . . .   5
       2.1.1.  Authorization Code Grant  . . . . . . . . . . . . . .   6
       2.1.2.  Implicit Grant  . . . . . . . . . . . . . . . . . . .   6
     2.2.  Token Replay Prevention . . . . . . . . . . . . . . . . .   7
     2.3.  Access Token Privilege Restriction  . . . . . . . . . . .   7
     2.4.  Resource Owner Password Credentials Grant . . . . . . . .   8
     2.5.  Client Authentication . . . . . . . . . . . . . . . . . .   8
     2.6.  Other Recommendations . . . . . . . . . . . . . . . . . .   8
   3.  The Updated OAuth 2.0 Attacker Model  . . . . . . . . . . . .   9
   4.  Attacks and Mitigations . . . . . . . . . . . . . . . . . . .  11
     4.1.  Insufficient Redirect URI Validation  . . . . . . . . . .  11
       4.1.1.  Redirect URI Validation Attacks on Authorization Code
               Grant . . . . . . . . . . . . . . . . . . . . . . . .  11
       4.1.2.  Redirect URI Validation Attacks on Implicit Grant . .  13
       4.1.3.  Countermeasures . . . . . . . . . . . . . . . . . . .  14
     4.2.  Credential Leakage via Referer Headers  . . . . . . . . .  15
       4.2.1.  Leakage from the OAuth Client . . . . . . . . . . . .  15
       4.2.2.  Leakage from the Authorization Server . . . . . . . .  15
       4.2.3.  Consequences  . . . . . . . . . . . . . . . . . . . .  16
       4.2.4.  Countermeasures . . . . . . . . . . . . . . . . . . .  16
     4.3.  Credential Leakage via Browser History  . . . . . . . . .  17
       4.3.1.  Authorization Code in Browser History . . . . . . . .  17
       4.3.2.  Access Token in Browser History . . . . . . . . . . .  17
     4.4.  Mix-Up Attacks  . . . . . . . . . . . . . . . . . . . . .  18
       4.4.1.  Attack Description  . . . . . . . . . . . . . . . . .  18
       4.4.2.  Countermeasures . . . . . . . . . . . . . . . . . . .  20
     4.5.  Authorization Code Injection  . . . . . . . . . . . . . .  21
       4.5.1.  Attack Description  . . . . . . . . . . . . . . . . .  21
       4.5.2.  Discussion  . . . . . . . . . . . . . . . . . . . . .  22
Show full document text