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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2018.1901 Denial of service vulnerabilities patched in Citrix XenServer 29 June 2018 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Citrix XenServer Publisher: Citrix Operating System: Virtualisation Impact/Access: Denial of Service -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2018-12893 CVE-2018-12891 Original Bulletin: https://support.citrix.com/article/CTX235748 - --------------------------BEGIN INCLUDED TEXT-------------------- CTX235748 Citrix XenServer Multiple Security Updates Security Bulletin | Priority: High Created: 28 Jun 2018 | Modified: 28 Jun 2018 Applicable Products * XenServer 7.5 * XenServer 7.4 * XenServer 7.3 * XenServer 7.1 LTSR Cumulative Update 1 * XenServer 7.0 Description of Problem Two issues have been identified within Citrix XenServer, which could, if exploited, allow unprivileged code in a PV guest VM to cause the host to crash or become unresponsive. These vulnerabilities affect all currently supported versions of Citrix XenServer up to and including Citrix XenServer 7.5. The following vulnerabilities have been addressed: * CVE-2018-12893: (High) x86: #DB exception safety check can be triggered by a guest * CVE-2018-12891: (Medium) preemption checks bypassed in x86 PV MM handling - ------------------------------------------------------------------------------- What Customers Should Do Hotfixes have been released to address these issues. Citrix recommends that affected customers install these hotfixes as soon as possible. The hotfixes can be downloaded from the following locations: * Citrix XenServer 7.5: CTX236153 ? https://support.citrix.com/article/ CTX236153 * Citrix XenServer 7.4: CTX236152 ? https://support.citrix.com/article/ CTX236152 * Citrix XenServer 7.3: CTX236151 ? https://support.citrix.com/article/ CTX236151 * Citrix XenServer 7.1 LTSR CU1: CTX236150 ? https://support.citrix.com/ article/CTX236150 * Citrix XenServer 7.0: CTX236149 ? https://support.citrix.com/article/ CTX236149 - ------------------------------------------------------------------------------- What Citrix Is Doing Citrix is notifying customers and channel partners about this potential security issue. This article is also available from the Citrix Knowledge Center at http://support.citrix.com/. - ------------------------------------------------------------------------------- Obtaining Support on This Issue If you require technical assistance with this issue, please contact Citrix Technical Support. Contact details for Citrix Technical Support are available at https://www.citrix.com/support/open-a-support-case.html. - ------------------------------------------------------------------------------- Reporting Security Vulnerabilities Citrix welcomes input regarding the security of its products and considers any and all potential vulnerabilities seriously. For guidance on how to report security-related issues to Citrix, please see the following document: CTX081743 ? Reporting Security Issues to Citrix - ------------------------------------------------------------------------------- Changelog +-----------------------------------------------------------------------------+ |Date |Change | |----------------------+------------------------------------------------------| |28th June 2018 |Initial issue | |----------------------+------------------------------------------------------| |28th June 2018 |Typo - Mark bulletin as High severity | +-----------------------------------------------------------------------------+ - ------------------------------------------------------------------------------- - --------------------------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. 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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 iQIVAwUBWzW8YmaOgq3Tt24GAQhnxhAAsYIZJGOwJh3rSiFymNW2NOPBzzrgN+u7 xLE4bh5+HctBcu1fzxpJLAYljyhiqadh/jW9vQmHo7HXMBuAsN0sqGC1EQUM4zR9 MbMFxHILcKKc69ddqnh84Mjg65WpqjA27LY1YptcA0FhHBWSA1s6nARbDE46zBar iSQi5flTMTSs5dDr4nc5A5qy9pciAveIxnGnE4kAbw2KFNnaofvX7H6pB07eQf6j 7l67qDP9MwX0lv8yHBfwh4o1pYOtKJue+PmsNenHE7NqeGze5qEy7viv9/T2CI6y QhGGjZitVVxNjvIkTOaezy5zS1vDpek8l0+U3ewpWWnj7fNFL7XNF5UDSBIsL6to LpoEU2/Ed9NfEMmK9U4BDKyB9qQYWF3XJDjxTqV05Qo6uzWkTm3xQzkeJD/ECzPB I5KG4fJjRZcsUaXwpjXwIgsTTdc0ttS89ylJ0vgxf2TNSS9AvjkjiFoE54PfQGGZ 6v2PmceYnHzMPQkh23cdoz0ZKC3Zk+dfSLgWBO63cqsMe8ljHc3a9HjvziWfkD3a SzTZ9B/Q/2ivpkcYX6WPFclMFXVAG/KkgeIDbp03JwYooFnzXDqfF9Gz8brX2kI3 SvNZgkx0UZK4t9n3zk9+xBek389oJyyqAxmdIPeYfa+D5TEbboGXq7enH2JCaTc7 YNnkIxNA/+8= =VQwo -----END PGP SIGNATURE-----