Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2020.4371.3 OpenSSL vulnerability CVE-2020-1968 18 January 2021 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: BIG-IP Publisher: F5 Networks Operating System: Network Appliance Impact/Access: Access Privileged Data -- Remote/Unauthenticated Resolution: Mitigation CVE Names: CVE-2020-1968 Reference: ESB-2020.4298 ESB-2020.3493 ESB-2020.3318 ESB-2020.3170 Original Bulletin: https://support.f5.com/csp/article/K92451315 Revision History: January 18 2021: Vendor issued minor update January 4 2021: Additional mitigation instructions added by vendor December 11 2020: Initial Release - --------------------------BEGIN INCLUDED TEXT-------------------- K92451315: OpenSSL vulnerability CVE-2020-1968 Original Publication Date: 11 Dec, 2020 Latest Publication Date: 16 Jan, 2021 Security Advisory Description The Raccoon attack exploits a flaw in the TLS specification which can lead to an attacker being able to compute the pre-master secret in connections which have used a Diffie-Hellman (DH) based ciphersuite. In such a case this would result in the attacker being able to eavesdrop on all encrypted communications sent over that TLS connection. The attack can only be exploited if an implementation re-uses a DH secret across multiple TLS connections. Note that this issue only impacts DH ciphersuites and not ECDH ciphersuites. This issue affects OpenSSL 1.0.2 which is out of support and no longer receiving public updates. OpenSSL 1.1.1 is not vulnerable to this issue. Fixed in OpenSSL 1.0.2w (Affected 1.0.2-1.0.2v). (CVE-2020-1968) Impact An attacker may be able to exploit OpenSSL Transport Layer Security (TLS), which allows unauthorized exposure of information when Diffie-Hellman (DH) secrets are reused across multiple TLS connections. Security Advisory Status F5 Product Development has assigned ID 945421 (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 |introduced|Severity |score^|component | | | |be |in | |1 |or feature | | | |vulnerable| | | | | +------------------+------+----------+----------+----------+------+-----------+ | |16.x |16.0.0 - |None | | | | | | |16.0.1 | | | | | | +------+----------+----------+ | | | | |15.x |15.1.0 - |None | | | | | | |15.1.2 | | | | | |BIG-IP (LTM, AAM, +------+----------+----------+ | | | |Advanced WAF, AFM,|14.x |14.1.0 - |None | | |TLS | |Analytics, APM, | |14.1.3 | | | |connections| |ASM, DDHD, DNS, +------+----------+----------+Medium |5.9 |(OpenSSL, | |FPS, GTM, Link |13.x |13.1.0 - |None | | |SSL | |Controller, PEM, | |13.1.3 | | | |profiles) | |SSLO) +------+----------+----------+ | | | | |12.x |12.1.0 - |None | | | | | | |12.1.5 | | | | | | +------+----------+----------+ | | | | |11.x |11.6.1 - |None | | | | | | |11.6.5 | | | | | +------------------+------+----------+----------+----------+------+-----------+ | |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 disable DH ciphersuites key exchanges in the vulnerable components. The Elliptic Curve Diffie-Hellman (ECDH) ciphersuites exchanges are not affected. To disable the DH ciphersuites in the SSL profile, perform the following procedure: Impact of procedure: Performing the following procedure should not have a negative impact on your system. The changes take effect when you associate the new SSL profile to a virtual server. 1. Log in to the Configuration utility. 2. Go to Local Traffic > Profiles > SSL > Client. 3. Select Create. 4. For the new profile, under General Properties, enter a name. 5. Set Configuration to Advanced. 6. For Ciphers, select the Custom check box. 7. For Ciphers, select Cipher Suites. Note: In BIG-IP 13.x, select Cipher String. In BIG-IP 11.x through 12.x, skip this step. 8. For Ciphers, enter a cipher string. For example, to disable the TLSv1 protocol and DHE ciphers, use the following syntax: DEFAULT:!TLSv1:!DHE 9. Configure the remaining profile settings. 10. Select Finished. For more information about configuring ciphers on SSL profiles, refer to K13171: Configuring the cipher strength for SSL profiles (11.x). Additionally, to mitigate this vulnerability, you should permit management access to F5 products only over a secure network and restrict command line access for affected systems to trusted users. For more information, refer to K13309: Restricting access to the Configuration utility by source IP address (11.x - 16.x) and K13092: Overview of securing access to the BIG-IP system. Supplemental Information o K41942608: Overview of security advisory articles o K91158923: BIG-IP SSL/TLS ADH/DHE vulnerability CVE-2020-5929 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 - 16.x) o K48955220: Installing an OPSWAT Endpoint Security update on BIG-IP APM systems (11.4.x and later) 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 iQIVAwUBYATURONLKJtyKPYoAQgRLA/9FHAFZ9KIXXTPaHf/GcIX5ljcKK2sbRo3 r1OjlZ3oNdmuqy5hozkCEa4Aoo0ZwIwUlITZizz4b+Pyc678Onav3MxV2oeRVfkb LmQsO5pCKW5PnL7C7iovsUiAHG+zspOqpFDFeKf8U0M78EOL3oW8OdcGyMpdd2nZ a1RyqTZB2nd6+ntlqtz53G1i/0yh9RyRv0/94Rc5ko0PkBJ9b2Udpwr23i3KX+yt gGdElc8IfgduzfaqxLGHomwB+OKmFFsS3EWkTkqf9TfwE7K0eqLMwqex+LNflaJy N3Hw5g3MhF1awx9aQHRyiYcjw92QPU55hPqxLGvMNljNo/JeH/Mj9p6K5TlBA1JO exQpixeGwveNzsARuR2z3v/FLYhfpeLogLNDYKDjAJOLCIc9ChqwawZl+1FV2IYX 3iKWVjOtZeqScil5kSDdyMrWBYIZThVTeSfAhpiIQULselrDS/ly5POyGgi/tuTI UmyFVmYQzO4cKaD3OZnQOQz2RejbJouOIfmSnH3V8BAuirMAB/l/90IohrpXuCVd cdbbaaYCHX493Zgs4Cewv0VPR+F3/u0gHX8FjhoKbUq+W0LCZsarOTZ1x1oVWHwz HISfrhzUfxR+JCWzKKDXXsb53TFoH0LA5cwu2SMuCdfKnnMr2rDnk/Dmj1qy8e2M 6yT+qb6WmWs= =gMEL -----END PGP SIGNATURE-----