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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2021.0681 Citrix Hypervisor Security Update 24 February 2021 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Citrix Hypervisor Publisher: Citrix Operating System: Virtualisation Citrix XenServer Impact/Access: Denial of Service -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2021-26932 CVE-2021-26931 CVE-2021-26930 Reference: ESB-2021.0586 ESB-2021.0585 ESB-2021.0582 Original Bulletin: https://support.citrix.com/article/CTX296603 - --------------------------BEGIN INCLUDED TEXT-------------------- Citrix Hypervisor Security Update Reference: CTX296603 Category : Medium Created : 16 February 2021 Modified : 23 February 2021 Applicable Products o Citrix Hypervisor Description of Problem Several security issues have been identified that, collectively, may allow privileged code running in a guest VM to cause the host to crash or to become unresponsive. These issues have the following CVE identifiers: CVE ID Description Vulnerability Pre-conditions Type An attacker with the ability to CWE-664: Improper Administrator CVE-2021-26930 execute privileged mode code in Control of a access in a guest can perform a denial of Resource Through guest service attack against the host its Lifetime An attacker with the ability to CWE-664: Improper Administrator CVE-2021-26931 execute privileged mode code in Control of a access in a guest can perform a denial of Resource Through guest service attack against the host its Lifetime An attacker with the ability to CWE-664: Improper Administrator CVE-2021-26932 execute privileged mode code in Control of a access in a guest can perform a denial of Resource Through guest service attack against the host its Lifetime All supported versions of Citrix Hypervisor are affected by these issues. What Customers Should Do Citrix has released hotfixes to address these issue. Citrix recommends that affected customers install these hotfixes as their patching schedule allows. The hotfixes can be downloaded from the following locations: Citrix Hypervisor 8.2 LTSR: CTX294145 - https://support.citrix.com/article/CTX294145 Citrix Hypervisor 7.1 LTSR: CTX294143 - https://support.citrix.com/article/CTX294143 Citrix Hypervisor 7.0: CTX294141 - https://support.citrix.com/article/CTX294141 Citrix is notifying customers and channel partners about this potential security issue. This article is also available from the Citrix Knowledge Center at . If you require technical assistance with this issue, please contact Citrix Technical Support. Contact details for Citrix Technical Support are available at . Citrix welcomes input regarding the security of its products and considers any and all potential vulnerabilities seriously. For details on our vulnerability response process and guidance on how to report security-related issues to Citrix, please see the following webpage: - This document is provided on an "as is" basis and does not imply any kind of guarantee or warranty, including the warranties of merchantability or fitness for a particular use. Your use of the information on the document is at your own risk. Citrix reserves the right to change or update this document at any time. Changelog Date Change 2021-02-16 Initial Publication Disclaimer 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. - --------------------------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 iQIVAwUBYDXfkONLKJtyKPYoAQh/9g/+MZj5HCS+KWVV99RvSLrMVC3WMpZlJlR4 0tuDuGcXMCSQJccYokn4QKaCrPGpv4/olz/tGET3ua59IDVPIQfafvrTUOJAMMaf Jv1nPyJxPem13P00VPXYXIdrapj5ucdAnkaHub3F8B+YAHcZuLKx4bOLCky68mqw rPGUG7rnFe8s73dtzyCpyNGreoDm1Oaoptn1DMwVMf3fJFjGydmpXc4oPq8KwhVQ V46/3HqA7PzFlHh1XD+MuYGVoOZCr3RumbMq0ebNGTJTm6C50ijNKyvJdaG3Si4n vLVWmGRoGkH9vt6Pi60wvcPdHwDzcRqNyQkr6QJp4GT7IBaz38FgRNeBJekh6aNb /mg2YoLQy+k5cI9dg7KNh9A0XZj6Vgucm9PJunihleMvQGGhK95oPTACkx22Qp/v HaRQndcny993v1iKjDbbMiyvjddXgJMrv2htOayYRsGXKfYj877BB8+kvSyaFVPd 9i0PhWeepWAQJCpIUt8oFkrMamLBRv9TPLYEPgSQIQgW69FP07CVS+fs7TWBXf7H gPIMxu19F9tGhZsIXMRItsufYYhaWXPBPjb+ycUqHhxWgWRATCqHC+yXsdcPjyhe bthUp5D4+3HHksUk6R9MfSny9skQccfkE5uNKlbLK/sMxGLWtMLe13OCZsTCXAD1 9koSa4O/nUo= =NtYn -----END PGP SIGNATURE-----