VMware ESXi Failed Login Attempts Denial of Service Vulnerability [CVE-2019-5528]

CVE Number – CVE-2019-5528

A vulnerability in VMware ESXi could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on a targeted system. The vulnerability exists because the affected software mishandles failed login attempts. An attacker could exploit this vulnerability by making multiple failed login attempts to an EXSi host. A successful exploit could allow the attacker to cause a DoS condition on the system. VMware has confirmed the vulnerability and released software updates.


  • To exploit this vulnerability, the attacker must have network access and the ability to perform multiple login attempts without being detected.  These requirements could reduce the likelihood of a successful exploit.


  • Administrators are advised to apply the appropriate updates.Administrators are advised to allow only trusted users to have network access.Administrators are advised to run both firewall and antivirus applications to minimize the potential of inbound and outbound threats.Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.Administrators can help protect affected systems from external attacks by using a solid firewall strategy.

Vendor Announcements

  • VMware has released a security advisory at the following link: VMSA-2019-0011

Fixed Software

  • VMware has released a software update at the following link: ESXi patch

Duncan Newell

Duncan is a technology professional with over 20 years experience of working in various IT roles. He has a interest in cyber security, and has a wide range of other skills in radio, electronics and telecommunications.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: