VMware has recently fixed a serious security flaw that may even lead to ransomware attacks. VMware urges all users to patch this serious RCE vulnerability in the vCenter Server.
VMware vCenter Server Vulnerability
In a recent blog post, VMware has shed light on a critical RCE vulnerability in the vCenter Server. Highlighting the importance of these patches, VMware stated,
In this era of ransomware, it is safest to assume that an attacker is already inside the network somewhere, on a desktop and perhaps even in control of a user account, which is why we strongly recommend declaring an emergency change and patching as soon as possible.
Specifically, vCenter Server is an advanced server management tool from VMware. It facilitates the management of virtual machines, ESXi hosts, and other components from a centralized location.
Briefly, the vendors highlight two security bugs in the vSphere Client (HTML5), CVE-2021-21985 and CVE-2021-21986, that allowed remote attacks.
The vendors describe the first bug, CVE-2021-21985, as a critical-severity remote code execution flaw that received a 9.8 CVSS score. This bug existed due to lack of input validation in the Virtual SAN Health Check plug-in in the vCenter Server.
Regarding its impact, VMware stated in an advisory,
A malicious actor with network access to port 443 may exploit this issue to execute commands with unrestricted privileges on the underlying operating system that hosts vCenter Server.
Whereas, the other vulnerability, CVE-2021-21986, existed in the authentication mechanism of Virtual SAN Health Check, Site Recovery, vSphere Lifecycle Manager, and VMware Cloud Director Availability plug-ins. The vendors have labeled this bug as a medium-severity flaw with a CVSS score of 6.5.
Explaining the impact of this bug upon exploitation, the advisory reads,
A malicious actor with network access to port 443 on vCenter Server may perform actions allowed by the impacted plug-ins without authentication.
These vulnerabilities affected the VMware vCenter Server version 6.5, 6.7, and 7.0, and VMware Cloud Foundation version 3.x and 4.x. Consequently, VMware patched these bugs with the latest releases.