Citrix XenServer Multiple Security Updates

Number: AV18-139
Date: 16 August 2018


The purpose of this advisory is to bring attention to recent security updates for Citrix XenServer.


The following updates are following up on Intel’s recent Security Advisory and addresses vulnerabilities in a speculative execution side-channel method called L1 Terminal Fault (L1TF). These vulnerabilities, if exploited, could allow malicious unprivileged code in guest VMs to read arbitrary host memory, including memory allocated to other guests.

Affected Products:

CVE References:
CVE-2018-3620, CVE-2018-3646, CVE-2018-14007, CVE-2018-TBA1, CVE-2018-TBA2

Suggested Action

CCIRC recommends that system administrators test and deploy the vendor-released updates to affected applications accordingly.           


Note to Readers

In support of Public Safety's mission to build a safe and resilient Canada, CCIRC's mandate is to help ensure the security and resilience of the vital non-federal government cyber systems that underpin Canada's national security, public safety and economic prosperity. As Canada's computer security incident response team, CCIRC is Canada's national coordination centre for the prevention and mitigation of, preparedness for, response to, and recovery from cyber incidents on non-federal government systems. It does this by providing authoritative advice and support, and coordinating information sharing and incident response.

Please note, CCIRC PGP key has recently been updated.

For general information, please contact Public Safety Canada's Public Affairs division at:

Telephone: 613-944-4875 or 1-800-830-3118
Fax: 613-998-9589

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