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AUSCERT External Security Bulletin Redistribution
ESB-2019.2505
Citrix Hypervisor Security Update
9 July 2019
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AusCERT Security Bulletin Summary
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Product: Citrix Hypervisor
Publisher: Citrix
Operating System: Citrix XenServer
Impact/Access: Denial of Service -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2019-11478 CVE-2019-11477
Reference: ASB-2019.0178
ASB-2019.0174
ASB-2019.0172
ESB-2019.2150
ESB-2019.2149.2
ESB-2019.2132.3
Original Bulletin:
https://support.citrix.com/article/CTX256725
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Citrix Hypervisor Security Update.
Reference: CTX256725
Category : Medium
Created : 08 Jul 2019
Modified : 08 Jul 2019
Applicable Products
o Citrix Hypervisor 8.0
o XenServer 7.1 LTSR Cumulative Update 2
o XenServer 7.0
o XenServer 7.6
Description of Problem
A vulnerability has been found in Citrix Hypervisor (formerly Citrix XenServer)
that may allow an unauthenticated attacker with the ability to send traffic to
a host over a management or storage network to cause the host to crash.
This vulnerability is identified as:
o CVE-2019-11477: SACK Panic
A secondary issue, which allows an unauthenticated attacker with the ability to
send traffic to a host over a management or storage network to cause a
transient increase in memory and processor load within the control domain, has
also been addressed. This issue is identified as:
o CVE-2019-11478: Excess resource usage
These issues affect all currently supported versions of Citrix Hypervisor up to
and including Citrix Hypervisor 8.0.
Mitigating Factors
Customers with isolated management networks, as recommended by Citrix, have
significantly mitigated this issue.
What Customers Should Do
Hotfixes have been released to address these issues. Citrix recommends that
affected customers install these hotfixes as their patching schedules allow.
The hotfixes can be downloaded from the following locations:
Citrix XenServer 8.0: CTX256714 - https://support.citrix.com/article/CTX256714
Citrix XenServer 7.6: CTX256713 - https://support.citrix.com/article/CTX256713
Citrix XenServer 7.1 LTSR CU2: CTX256712 - https://support.citrix.com/article/
CTX256712
Citrix XenServer 7.0: CTX256711 - https://support.citrix.com/article/CTX256711
Changelog
+-------------------------------+---------------------------------------------+
|Date |Change |
+-------------------------------+---------------------------------------------+
|8th July 2019 |Initial Publication |
+-------------------------------+---------------------------------------------+
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