Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2020.4496
zxfrd vulnerability CVE-2020-27725
18 December 2020
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: BIG-IP Products
Publisher: F5 Networks
Operating System: Network Appliance
Impact/Access: Denial of Service -- Existing Account
Resolution: Patch/Upgrade
CVE Names: CVE-2020-27725
Original Bulletin:
https://support.f5.com/csp/article/K25595031
- --------------------------BEGIN INCLUDED TEXT--------------------
K25595031: zxfrd vulnerability CVE-2020-27725
Original Publication Date: 17 Dec, 2020
Security Advisory Description
zxfrd leaks memory when listing DNS zones. Zones can be listed via TMSH,
iControl or SNMP; only users with access to those services can trigger this
vulnerability. (CVE-2020-27725)
Impact
The memory leak by the zxfrd process eventually causes the system to
experience an out-of-memory condition. As a result, systems in a high
availability (HA) configuration may experience a failover. This vulnerability
affects only BIG-IP systems that are provisioned with BIG-IP DNS or BIG-IP GTM
and at least one DNS zone.
Security Advisory Status
F5 Product Development has assigned ID 904937 (BIG-IP) to this vulnerability.
To determine if your product and version have been evaluated for this
vulnerability, refer to the Applies to (see versions) box. To determine if your
release is known to be vulnerable, the components or features that are affected
by the vulnerability, and for information about releases, point releases, or
hotfixes that address the vulnerability, refer to the following table. For more
information about security advisory versioning, refer to K51812227:
Understanding Security Advisory versioning.
+------------------+------+-----------+----------+----------+------+-----------+
| | |Versions |Fixes | |CVSSv3|Vulnerable |
|Product |Branch|known to be|introduced|Severity |score^|component |
| | |vulnerable |in | |1 |or feature |
+------------------+------+-----------+----------+----------+------+-----------+
| |16.x |None |16.0.0 | | | |
| +------+-----------+----------+ | | |
| |15.x |15.0.0 - |15.1.1 | | | |
| | |15.1.0 | | | | |
| +------+-----------+----------+ | | |
| |14.x |14.1.0 - |14.1.3.1 | | | |
| | |14.1.3 | | | | |
|BIG-IP (DNS, GTM, +------+-----------+----------+Medium |4.3 |zxfrd |
|Link Controller) |13.x |13.1.0 - |13.1.3.5 | | | |
| | |13.1.3 | | | | |
| +------+-----------+----------+ | | |
| |12.x |12.1.0 - |None | | | |
| | |12.1.5 | | | | |
| +------+-----------+----------+ | | |
| |11.x |11.6.1 - |None | | | |
| | |11.6.5 | | | | |
+------------------+------+-----------+----------+----------+------+-----------+
| |16.x |None |Not | | | |
| | | |applicable| | | |
| +------+-----------+----------+ | | |
| |15.x |None |Not | | | |
| | | |applicable| | | |
| +------+-----------+----------+ | | |
|BIG-IP (LTM, AAM, |14.x |None |Not | | | |
|AFM, Analytics, | | |applicable|Not | | |
|APM, ASM, FPS, +------+-----------+----------+vulnerable|None |None |
|PEM) |13.x |None |Not | | | |
| | | |applicable| | | |
| +------+-----------+----------+ | | |
| |12.x |None |Not | | | |
| | | |applicable| | | |
| +------+-----------+----------+ | | |
| |11.x |None |Not | | | |
| | | |applicable| | | |
+------------------+------+-----------+----------+----------+------+-----------+
| |7.x |None |Not | | | |
| | | |applicable| | | |
| +------+-----------+----------+ | | |
|BIG-IQ Centralized|6.x |None |Not |Not |None |None |
|Management | | |applicable|vulnerable| | |
| +------+-----------+----------+ | | |
| |5.x |None |Not | | | |
| | | |applicable| | | |
+------------------+------+-----------+----------+----------+------+-----------+
|Traffix SDC |5.x |None |Not |Not |None |None |
| | | |applicable|vulnerable| | |
+------------------+------+-----------+----------+----------+------+-----------+
^1The CVSSv3 score link takes you to a resource outside of AskF5, and it is
possible that the document may be removed without our knowledge.
Security Advisory Recommended Actions
If you are running a version listed in the Versions known to be vulnerable
column, you can eliminate this vulnerability by upgrading to a version listed
in the Fixes introduced in column. If the table lists only an older version
than what you are currently running, or does not list a non-vulnerable version,
then no upgrade candidate currently exists.
Mitigation
To mitigate this vulnerability, you can restrict access to the Traffic
Management Shell (tmsh), iControl, and SNMP over a secure network and/or limit
to trusted users. For more information about securing access to BIG-IP systems,
refer to the following articles:
o K46122561: Restricting access to the management port using network firewall
rules
o K17459: Restricting access to the iControl SOAP API by source IP address
o K13535: Restricting SNMP access to the BIG-IP system
o K13309: Restricting access to the Configuration utility by source IP
address (11.x - 15.x)
o K13092: Overview of securing access to the BIG-IP system
Supplemental Information
o K51812227: Understanding Security Advisory versioning
o K41942608: Overview of 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 - 15.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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=E7wU
-----END PGP SIGNATURE-----