Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2020.0171 FortiSIEM default SSH key for the "tunneluser" account is the same across all appliances 16 January 2020 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: FortiSIEM Publisher: FortiNet Operating System: FortiOS Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2019-17659 Original Bulletin: https://fortiguard.com/psirt/FG-IR-19-296 - --------------------------BEGIN INCLUDED TEXT-------------------- FortiSIEM default SSH key for the "tunneluser" account is the same across all appliances IR Number : FG-IR-19-296 Date : Jan 15, 2020 Risk : 2/5 Impact : Denial of Service CVE ID : CVE-2019-17659 CVE ID : CVE-2019-17659 Summary A use of hard-coded cryptographic key vulnerability in FortiSIEM may allow a remote unauthenticated attacker to obtain SSH access to the supervisor as the restricted user "tunneluser" by leveraging knowledge of the private key from another installation or a firmware image. Note: Restricted user "tunneluser" runs in a restricted shell that lets only that user create tunnel connections from the supervisor to the originating IP (i.e. enabling reverse-shell connections to the IP that initiated the connection). This is a feature that exists to enable connecting to collectors from the supervisor when there is a firewall between the collector and the supervisor. Impact Denial of Service Affected Products FortiSIEM version 5.2.6 and below. Solutions Please upgrade to FortiSIEM version 5.2.7 and above where this issue is resolved. Workaround (for FortiSIEM version 5.2.6 and lower): Customers who are not using the reverse tunnel feature are advised to disable SSH service on port 19999 by following the steps below : 1. SSH to the Supervisor node as the root user. 2. Remove tunneluser SSH configuration file to disable listening on port 19999: rm -f /etc/ssh/sshd_config.tunneluser echo rm -f /etc/ssh/sshd_config.tunneluser >> /etc/init.d/phProvision.sh 3. Then terminate sshd running on TCP Port 19999 as follows: pkill -f /usr/sbin/sshd -p 19999 4.Additional steps can be performed on Supervisor to remove the keys associated with tunneluser account: rm -f /opt/phoenix/deployment/id_rsa.pub.tunneluser rm -f /home/tunneluser/.ssh/authorized_keys rm -f /opt/phoenix/id_rsa.tunneluser ~admin/.ssh/id_rsa Customers are also advised to disable "tunneluser" SSH access on port 22 by following the steps bwlow: 1. SSH to the Supervisor node as the root user. 2. Add/edit the following line in sshd_config file: echo DenyUsers tunneluser >> /etc/ssh/sshd_config 3. service sshd restart Acknowledgement Fortinet is pleased to thank Andrew Klaus for bringing this issue to our attention. - --------------------------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 iQIVAwUBXh/YBWaOgq3Tt24GAQifZxAAg2nvPZGGs0qSPZQFV4RMQftXGTKCmLHt 5Qqb2ZG9Fop1mMT/kSkW8fj+ZXEHfecmlLbfMDKPc6k5eNtpPJWeCy1lHJVZbLAs ymNi5JvUXwcmkZ/bW7W6lH4Tz8rghjdzST5NbEhocrHOZaahglWRfI6v3Vf/wp/G dACK2bl5Ge8iZip2jWh1qpxGBeDSCz5KzIMgeSKc58AtqICZwejaVeE2fkATNNnh oN1kYqP9OLf1mySMeIuD+GX/8FsgPeYx+eGIlkjneP9cMIlLiSnRHQAkygMqLzQ1 kEA8E+YgG+ajWpCTm0pI0swwWtHHYCHYshYhxRl3CVkYwYrcStn55LPKct/Ok84q Wgs3W6s04TM3vSzvXrdN1u51nhvLpAjNzLTDY6HAtNoN+RZXuB3tzzQq4xbuO2J3 4n8KLyBe/sxZdXrJTN/An5hAqCj0nqxqDjAN1mk4Vtk0YlRujv51+7FEcy1fh0KW cueUHS3qN8MD9ZiaJ54YAiCaWSY6COsubuE9yL5DfaVXwBoRt1Jj26G68h8cRlYo 5bSiEv2v2+Z8oFuSLqt4REC2ZuvWdLrNG/cKGFPUKXoP9gGxj8igp+Pp0YvGcVl4 /bQeYllbz5pblZOqB1ArrdFA6vOptwr98WdWn4LeL9LeJj5fGdDV1X46Y2f5cfbW Z86C6Oud9sE= =83+A -----END PGP SIGNATURE-----