1. Impacted Products

• ESXi

2. Introduction

A partial denial of service vulnerability in ESXi was reported to VMware Security Response. Patches and workarounds are currently available to remediate or workaround this vulnerability.

3. Partial denial of service vulnerability in ESXi hostd process (CVE-2019-5528)

Description:

Multiple failed login attempts to ESXi may cause the hostd service to become unresponsive resulting in a partial denial of service for management functionality. VMware has evaluated the severity of this issue to be in the Moderate severity range with a maximum CVSSv3 base score of 5.3.

Known Attack Vectors:

A malicious actor with network access to an ESXi host could create a partial denial of service condition in management functionality. Successful exploitation of this issue may cause hostd to become unresponsive resulting in conditions such as an ESXi host disconnecting from vCenter.

Resolution:

To remediate this vulnerability, apply the patches listed in the 'Fixed Version' column of the 'Resolution Matrix' found below.

Workarounds:

Workarounds are available for this issue, follow the instructions in the documents linked in the 'Workarounds' section found below.

Additional Documentations:

None.

Acknowledgements:

None.
 

Notes:

• If hostd becomes unresponsive due to CVE-2019-5528 the condition can be cleared by restarting the hostd service, it is not necessary to reboot the ESXi host.
• Vulnerability scanners have been reported to trigger this vulnerability via multiple failed login attempts to ESXi.
  
  

Response Matrix:

4. References

Mitre CVE Dictionary Links:

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-5528

Fixed Version(s) and Release Notes:

ESXi670-201908201-UG:

Downloads:

https://my.vmware.com/group/vmware/patch

Documentation:

https://docs.vmware.com/en/VMware-vSphere/6.7/rn/vsphere-esxi-67u3-release-notes.html

ESXi650-201907201-UG:
Downloads:

https://my.vmware.com/group/vmware/patch

Documentation:

https://docs.vmware.com/en/VMware-vSphere/6.5/rn/vsphere-esxi-65u3-release-notes.html

Workarounds:

https://kb.vmware.com/s/article/67920

5. Change log
 

2019-07-09: VMSA-2019-0011

Initial security advisory detailing remediations and workarounds available for ESXi.

2019-09-03: VMSA-2019-0011.1

Updated security advisory detailing ESXi 6.7 remediation information.

6. Contact

E-mail list for product security notifications and announcements:

https://lists.vmware.com/cgi-bin/mailman/listinfo/security-announce

This Security Advisory is posted to the following lists:

  security-announce@lists.vmware.com

  bugtraq@securityfocus.com

  fulldisclosure@seclists.org

E-mail: security@vmware.com

PGP key at:

https://kb.vmware.com/kb/1055

VMware Security Advisories

https://www.vmware.com/security/advisories

VMware Security Response Policy

https://www.vmware.com/support/policies/security_response.html

VMware Lifecycle Support Phases

https://www.vmware.com/support/policies/lifecycle.html

VMware Security & Compliance Blog  

https://blogs.vmware.com/security

Twitter

https://twitter.com/VMwareSRC

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