VMware Security Advisory:- VMSA-2010-0020

New Security Advisory this one is just for ESXi 4.1.  The basic crux of this issue is that under certain circumstances and upgrade from a 3.5 or 4.0 host to a 4.1 the installer incorrectly handles SFCB authentication modes, This can result in a situation were SFCB authentication can allow authentication with any username/password combination.  For further details of the issue I urge you to read the Knowledge base article liked in the advisory copied out below.

Synopsis: VMware ESXi 4.1 Update Installer SFCB Authentication Flaw
Issue date: 2010-12-21
Updated on: 2010-12-21
CVE numbers: CVE-2010-4573

1. Summary

VMware ESXi 4.1 Update Installer might introduce a SFCB Authentication Flaw.

2. Relevant releases

VMware ESXi 4.1 if upgraded from ESXi 3.5 or ESXi 4.0 with a modified SFCB configuration file.

3. Problem Description

a. ESXi 4.1 Update Installer SFCB Authentication Flaw Under certain conditions, the ESXi 4.1 installer that upgrades an ESXi 3.5 or ESXi 4.0 host to ESXi 4.1 incorrectly handles the SFCB authentication mode. The result is that SFCB authentication could allow login with any username and password combination.

An ESXi 4.1 host is affected if all of the following apply:

  • – ESXi 4.1 was upgraded from ESXi 3.5 or ESXi 4.0.
  • – The SFCB configuration file /etc/sfcb/sfcb.cfg was modified prior to the upgrade.
  • – The sfcbd daemon is running (sfcbd runs by default).


A workaround that can be applied to ESXi 4.1 is described in VMware Knowledge Base Article KB 1031761

The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2010-4573 to this issue.

Column 4 of the following table lists the action required to remediate the vulnerability in each release, if a solution is available.

VMware Product Product Version Running on Replace with/Apply Patch
VirtualCenter any Windows not affected
hosted * any any not affected
ESXi 4.1 ESXi see KB 1031761 for workaround **
ESXi 4.0 ESXi not affected
ESXi 3.5 ESXi not affected
ESX any ESX not affected

* hosted products are VMware Workstation, Player, ACE, Server, Fusion.

** ESXi 4.1 is only affected if upgraded from ESXi 3.5 or ESXi 4.0 with a modified SFCB configuration file.

4. Solution

Please review the patch/release notes for your product and version and verify the md5sum of your downloaded file. ESXi 4.1

Workaround described in VMware Knowledge Base Article KB 1031761


5. References

CVE numbers


6. Change log

2010-12-21 VMSA-2010-0020

Initial security advisory after release of VMware knowledge base article that documents workaround on 2010-12-21.

7. Contact

E-mail list for product security notifications and announcements:


This Security Advisory is posted to the following lists:

  • * security-announce at lists.vmware.com
  • * bugtraq at securityfocus.com
  • * full-disclosure at lists.grok.org.uk

E-mail: security at vmware.com
PGP key at: http://kb.vmware.com/kb/1055

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Copyright 2010 VMware Inc. All rights reserved.

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