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             AUSCERT External Security Bulletin Redistribution

          K23432927: The BIG-IP ASM system may redirect a client
                        request to an incorrect URL
                              31 January 2019


        AusCERT Security Bulletin Summary

Product:           F5 BIG-IP ASM
Publisher:         F5 Networks
Operating System:  Network Appliance
Impact/Access:     Provide Misleading Information -- Remote with User Interaction
Resolution:        Patch/Upgrade

Original Bulletin: 

- --------------------------BEGIN INCLUDED TEXT--------------------

K23432927: The BIG-IP ASM system may redirect a client request to an incorrect

Security Advisory

Original Publication Date: Jan 30, 2019

Applies to (see versions):

  o Product: BIG-IP, BIG-IP ASM
      o 12.1.2, 12.1.1, 12.1.0, 11.6.2, 11.6.1, 11.5.4, 11.5.3, 11.5.2, 11.5.1

Security Advisory Description

The BIG-IP ASM system may redirect a client request to an incorrect URL after
the client browser passes the client-side integrity defense JavaScript

This issue occurs when all of the following conditions are met:

  o You have enabled the Client Side Integrity Defense feature in a DoS profile
    associated with a virtual server.
  o A client request containing a certain structured URL is processed by the
    virtual server with the DoS profile.
  o The client browser passes the client-side integrity defense JavaScript
    challenge issued by the BIG-IP ASM system.


The client browser is redirected to an incorrect URL. If a malicious attacker
triggers the DoS profile and then sends a maliciously crafted structured URL to
unsuspecting users as part of a phishing attack, the users may be redirected to
a malicious website.


As a result of this issue, you may encounter the following symptom:

  o The client browser is redirected to an incorrect URL instead of the
    original website.

Security Advisory Status

F5 Product Development has assigned ID 648617 and 669394  to this issue. F5 has
confirmed that this issue exists in the products listed in the Applies to (see
versions) box, located in the upper-right corner of this article. For
information about releases, point releases, or hotfixes that resolve this
issue, refer to the following table.

|Type of fix       |Fixes introduced  |Related articles                       |
|                  |in                |                                       |
|                  |13.0.0            |                                       |
|Release           |12.1.3            |K2200: Most recent versions of F5      |
|                  |11.6.3            |software                               |
|                  |11.5.5            |                                       |
|Point release/    |None              |None                                   |
|hotfix            |                  |                                       |

Security Advisory Recommended Actions




F5 would like to acknowledge An Trinh of Viettel Cyber Security for bringing
this issue to our attention and following the highest standards of responsible

Supplemental Information

  o K51812227: Understanding Security Advisory versioning
  o K41942608: Overview of AskF5 Security Advisory articles
  o K4602: Overview of the F5 security vulnerability response policy
  o K4918: Overview of the F5 critical issue hotfix policy
  o K9502: BIG-IP hotfix and point release matrix
  o K13123: Managing BIG-IP product hotfixes (11.x - 13.x)
  o K167: Downloading software and firmware from F5
  o K9970: Subscribing to email notifications regarding F5 products
  o K9957: Creating a custom RSS feed to view new and updated documents

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