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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2020.2136.4 BIND vulnerability CVE-2020-8619 4 November 2020 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: F5 Big-IP Products Publisher: F5 Networks Operating System: Network Appliance Impact/Access: Denial of Service -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2020-8619 Reference: ESB-2020.2105 ESB-2020.2104 Original Bulletin: https://support.f5.com/csp/article/K19807532 Revision History: November 4 2020: Vendor updated to include BIG-IP branch 16.x August 28 2020: Patch released for the 15.1.x branch but not 15.0.x August 20 2020: A fix is available for the 14.x branch June 19 2020: Initial Release - --------------------------BEGIN INCLUDED TEXT-------------------- K19807532:BIND vulnerability CVE-2020-8619 Security Advisory Original Publication Date: 19 Jun, 2020 Latest Publication Date: 03 Nov, 2020 Security Advisory Description The asterisk character ("*") is allowed in DNS zone files, where it is most commonly present as a wildcard at a terminal node of the Domain Name System graph. However, the RFCs do not require and BIND does not enforce that an asterisk character be present only at a terminal node. A problem can occur when an asterisk is present in an empty non-terminal location within the DNS graph. If such a node exists, after a series of queries, named can reach an inconsistent state that results in the failure of an assertion check in rbtdb.c, followed by the program exiting due to the assertion failure. (CVE-2020-8619) Impact You encounter this defect when you have both of the following conditions: o A nameserver provides authoritative service for one or more zones. o At least one zone contains an empty non-terminal entry containing an asterisk character. A would-be attacker who is allowed to change zone content could, theoretically, introduce such a record in order to exploit this condition to cause denial-of-service (DoS); however, the use of this vector is unlikely because any such attack requires a significant privilege-level and is easily traceable. BIND versions from 9.11.14 through 9.11.19 are impacted. Security Advisory Status F5 Product Development has assigned ID 917005 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 |introduced|Severity |score^|component | | | |be |in | |1 |or feature| | | |vulnerable| | | | | +------------------+------+----------+----------+-----------+------+----------+ | |16.x |16.0.0 |16.0.1 | | | | | +------+----------+----------+ | | | | | |15.1.0 |15.1.0.5 | | | | | |15.x |15.0.0 - |None | | | | | | |15.0.1 | | | | | | +------+----------+----------+ | | | |BIG-IP (LTM, AAM, |14.x |14.1.0 - |14.1.2.7 | | | | |AFM, Analytics, | |14.1.2 | | | | | |APM, ASM, DNS, +------+----------+----------+Medium |4.3 |BIND | |FPS, GTM, Link |13.x |13.1.0 - |None | | | | |Controller, PEM) | |13.1.3 | | | | | | +------+----------+----------+ | | | | |12.x |12.1.0 - |None | | | | | | |12.1.5 | | | | | | +------+----------+----------+ | | | | |11.x |11.6.1 - |None | | | | | | |11.6.5 | | | | | +------------------+------+----------+----------+-----------+------+----------+ | |7.x |None |Not | | | | | | | |applicable| | | | | +------+----------+----------+Not | | | |BIG-IQ Centralized|6.x |None |Not |vulnerable^|None |None | |Management | | |applicable|2 | | | | +------+----------+----------+ | | | | |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. ^2The specified products contain the affected code. However, F5 identifies the vulnerability status as Not vulnerable because the attacker cannot exploit the code in default, standard, or recommended configurations. 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, when you configure a non-terminal location for any zones in your zone file, avoid using an empty non-terminal record containing an asterisk character. The following example displays an empty non-terminal record that could trigger this vulnerability: foo.*.example.com For more information about empty non-terminal records, refer to What is an Empty Non-Terminal. Supplemental Information 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 iQIVAwUBX6Hx6uNLKJtyKPYoAQhbgQ//XpXoCAcphKbs43d+fjBsvAoRR0RKuKs/ TJ7e3lPMHdESWXTkj8IrSgvZH9OwLkqWxzAlQC/CacnmJIg9fOyFcBZ/DZmuRXs1 Zz+vwT1bOAUCK8vE1bMqJ6UBP8vRq1UL3wt1XK1aO/6ZgnVXPYTMQUh828dP86W/ ZGoNVzz36Q30kqXo3rYp5qKDTzNkgp47DUo/LyWk9X6Nu+Lz1Mq0GKislManzCk9 YymU/eAdBfJTIkIK89hmHW8GGFqAxYiknJYMNota1BXzx0Lea4YoV2tK1Bk8LbuF N2CwXyGWU9LNxkAAmxttxRJDu4ZuQUF4K87Y6oNYyLWgg97JvAe89acre4b9cyMb iwX7IpgHfc7qCqczv0ujNziwDIvsylEaaDKi8FQmnkkfI36qwBBeVTi1Dg58TJZG eSUNIhxNPdpl+bKTugPsdYmS5Y92uuJ7tgNFwK1CxDM6RpBq1VQ6yL6o3QdjbrXK sjDxZ9jIef3nhQFhCUsMNmN843XEKz0jmbI2lEoVVIhP0QDQFu/uH19sJfQKvGVF aQUY/dNyeBoT4NFXZtLHFxXHFcPS51foxfHVs22JmI+713WZGELjHNOUpdWtIxO6 YUo4ps3kYQtFj83Xp6Uk/bBjYMhllvHAw68ZledM9JcnI3nHfS40V1b4dTxI8GrW 4N4eSmIMbrY= =wMbv -----END PGP SIGNATURE-----