Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2018.3179
Session data may be exposed when using a proxy to multiplex
connections to the BIG-IP APM system
18 October 2018
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: F5 BIG-IP products
Publisher: F5 Networks
Operating System: Network Appliance
Impact/Access: Access Confidential Data -- Remote with User Interaction
Resolution: Mitigation
Original Bulletin:
https://support.f5.com/csp/article/K13217575
- --------------------------BEGIN INCLUDED TEXT--------------------
K13217575:Session data may be exposed when using a proxy to multiplex
connections to the BIG-IP APM system
Security Advisory
Original Publication Date: 18 Oct, 2018
Security Advisory Description
This issue occurs when all of the following conditions are met:
o The BIG-IP APM system is configured to perform NTLM SSO authentication to
back-end servers.
o A proxy in front of the BIG-IP APM system multiplexes connections from
different users.
Impact
Users may be exposed to session data from other user connections.
Symptoms
As a result of this issue, you may encounter the following symptom:
o Users connecting to the BIG-IP APM system see other user's session data or
application data.
Security Advisory Status
F5 Product Development has assigned ID 710984 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 in|Related articles|
+--------------------+-------------------+----------------+
|Release |None |None |
+--------------------+-------------------+----------------+
|Point release/hotfix|None |None |
+--------------------+-------------------+----------------+
Security Advisory Recommended Actions
Workaround
To work around this issue when using IIS servers on the back end, you can
configure the authPersistSingleRequest=TRUE metabase property on the IIS
server. To work around this issue using an iRule, you can create an iRule
using the following code and associate it with the virtual server. To do so,
perform the following procedure:
Impact of workaround: The impact of the suggested workaround depends on the
specific environment. F5 recommends that you test any such changes during a
maintenance window and consider the possible impact to your environment.
1. Log in to the BIG-IP Configuration utility.
2. Navigate to Local Traffic > iRules.
3. Click Create.
4. Type a name in the Name field.
5. Enter the following code in the Definition field:
when HTTP_REQUEST {
if { not ([HTTP::cookie exists "MRHSession"]) } {
return
}
set sid [HTTP::cookie "MRHSession"]
if { not ([ACCESS::session exists -state_allow -sid $sid]) } {
return
}
set laddr [IP::local_addr]
set lport [TCP::local_port]
set raddr [IP::remote_addr]
set rport [TCP::remote_port]
set tuple_hash [sha256 "$laddr:$lport,$raddr:$rport"]
set key "access_session.for.flow.$tuple_hash"
set result [table add $key $sid]
if { $result eq $sid } {
# letting request go
return
}
# this request requires detaching serverside flow, then re-attaching
set selected [LB::select]
LB::detach
eval $selected
table set $key $sid
}
# clean-up iRule for when the connection closes
when CLIENT_CLOSED {
set laddr [IP::local_addr]
set lport [TCP::local_port]
set raddr [IP::remote_addr]
set rport [TCP::remote_port]
set tuple_hash [sha256 "$laddr:$lport,$raddr:$rport"]
set key "access_session.for.flow.$tuple_hash"
table delete $key
}
6. Click Finished.
7. Navigate to Local Traffic > Virtual Servers.
8. Click Edit in the Resources column for the affected virtual server.
9. Under iRules, click Manage.
10. Click the name of the newly created iRule and click << to move it to the
Enabled box.
11. Click Finished.
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
- --------------------------END INCLUDED TEXT--------------------
You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.
NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members. As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.
NOTE: This is only the original release of the security bulletin. It may
not be updated when updates to the original are made. If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.
Contact information for the authors of the original document is included
in the Security Bulletin above. If you have any questions or need further
information, please contact them directly.
Previous advisories and external security bulletins can be retrieved from:
https://www.auscert.org.au/bulletins/
===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072
Internet Email: auscert@auscert.org.au
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967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=wQX/
-----END PGP SIGNATURE-----