| V-258749 | High | The ESXi host must maintain the confidentiality and integrity of information during transmission by exclusively enabling Transport Layer Security (TLS) 1.2. | TLS 1.0 and 1.1 are deprecated protocols with well-published shortcomings and vulnerabilities. TLS 1.2 should be enabled on all interfaces and SSLv3, TL 1.1, and 1.0 disabled, where... |
| V-258746 | High | The ESXi Image Profile and vSphere Installation Bundle (VIB) acceptance level must be verified. | Verify the ESXi Image Profile to only allow signed VIBs. An unsigned VIB represents untested code installed on an ESXi host. The ESXi Image profile supports four acceptance levels:
1.... |
| V-258732 | High | The ESXi host Secure Shell (SSH) daemon must use FIPS 140-2 validated cryptographic modules to protect the confidentiality of remote access sessions. | Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session.
OpenSSH on the ESXi host ships with a FIPS 140-2... |
| V-258776 | High | The ESXi host must have all security patches and updates installed. | Installing software updates is a fundamental mitigation against the exploitation of publicly known vulnerabilities. |
| V-258772 | High | The ESXi host must configure virtual switch security policies to reject Media Access Control (MAC) address changes. | If the virtual machine (VM) operating system changes the MAC address, it can send frames with an impersonated source MAC address at any time. This allows it to stage malicious attacks on the... |
| V-258769 | Medium | The ESXi host must configure the firewall to block network traffic by default. | In addition to service-specific firewall rules, ESXi has a default firewall rule policy to allow or deny incoming and outgoing traffic. Reduce the risk of attack by ensuring this is set to deny... |
| V-258753 | Medium | The ESXi host Secure Shell (SSH) daemon must display the Standard Mandatory DOD Notice and Consent Banner before granting access to the system. | Display of a standardized and approved use notification before granting access to the host ensures privacy and security notification verbiage used is consistent with applicable federal laws,... |
| V-258789 | Medium | The ESXi host must enable strict x509 verification for SSL syslog endpoints. | When sending syslog data to a remote host via SSL, the ESXi host is presented with the endpoint's SSL server certificate. In addition to trust verification, configured elsewhere, this... |
| V-258788 | Medium | The ESXi host must off-load audit records via syslog. | ESXi offers both local and remote audit recordkeeping to meet the requirements of the NIAP Virtualization Protection Profile and Server Virtualization Extended Package. Local records are stored on... |
| V-258787 | Medium | The ESXi host must enable audit logging. | ESXi offers both local and remote audit recordkeeping to meet the requirements of the NIAP Virtualization Protection Profile and Server Virtualization Extended Package. Local records are stored on... |
| V-258786 | Medium | The ESXi host OpenSLP service must be disabled. | OpenSLP implements the Service Location Protocol to help CIM clients discover CIM servers over TCP 427. This service is not widely needed and has had vulnerabilities exposed in the past. To reduce... |
| V-258785 | Medium | The ESXi host Secure Shell (SSH) daemon must disable port forwarding. | While enabling Transmission Control Protocol (TCP) tunnels is a valuable function of sshd, this feature is not appropriate for use on the ESXi hypervisor. |
| V-258784 | Medium | The ESXi host must use DOD-approved certificates. | The default self-signed host certificate issued by the VMware Certificate Authority (VMCA) must be replaced with a DOD-approved certificate when the host will be accessed directly, such as during... |
| V-258783 | Medium | The ESXi Common Information Model (CIM) service must be disabled. | The CIM system provides an interface that enables hardware-level management from remote applications via a set of standard application programming interfaces (APIs). These APIs are consumed by... |
| V-258782 | Medium | The ESXi host must be configured with an appropriate maximum password age. | The older an ESXi local account password is, the larger the opportunity window is for attackers to guess, crack or reuse a previously cracked password. Rotating passwords on a regular basis is a... |
| V-258781 | Medium | The ESXi host must configure a session timeout for the vSphere API. | The vSphere API (VIM) allows for remote, programmatic administration of the ESXi host. Authenticated API sessions are no different from a risk perspective than authenticated UI sessions and they... |
| V-258780 | Medium | The ESXi host must enable volatile key destruction. | By default, pages allocated for virtual machines (VMs), userspace applications, and kernel threads are zeroed out at allocation time. ESXi will always ensure that no nonzero pages are exposed to... |
| V-258800 | Medium | The ESXi host must not enable log filtering. | The log filtering capability allows users to modify the logging policy of the syslog service that is running on an ESXi host. Users can create log filters to reduce the number of repetitive... |
| V-258754 | Medium | The ESXi host must be configured to disable nonessential capabilities by disabling Secure Shell (SSH). | The ESXi Shell is an interactive command line interface (CLI) available at the ESXi server console. The ESXi shell provides temporary access to commands essential for server maintenance. Intended... |
| V-258729 | Medium | The ESXi host must display the Standard Mandatory DOD Notice and Consent Banner before granting access to the system via the Direct Console User Interface (DCUI). | Display of a standardized and approved use notification before granting access to the host ensures privacy and security notification verbiage used is consistent with applicable federal laws,... |
| V-258728 | Medium | The ESXi host must enforce the limit of three consecutive invalid logon attempts by a user. | By limiting the number of failed logon attempts, the risk of unauthorized access via user password guessing, otherwise known as brute forcing, is reduced. Once the configured number of attempts is... |
| V-265976 | Medium | The ESXi host must deny shell access for the dcui account. | The dcui user is used for process isolation for the DCUI itself. The account has shell access which can be deactivated to reduce attack surface. |
| V-265977 | Medium | The ESXi host must disable virtual hardware management network interfaces. | Hardware management controllers often present virtual or USB NICs to the ESXi host. These can be used as backdoors and should be deactivated both in the hardware configuration and in ESXi. |
| V-258757 | Medium | The ESXi host must set a timeout to automatically end idle DCUI sessions after 10 minutes. | When the Direct Console User Interface (DCUI) is enabled and logged in, it should be automatically logged out if left logged on to avoid access by unauthorized persons. The "DcuiTimeOut" setting... |
| V-258761 | Medium | The ESXi host Secure Shell (SSH) daemon must not allow host-based authentication. | SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts. SSH's cryptographic host-based authentication is more secure than ".rhosts"... |
| V-258760 | Medium | The ESXi host lockdown mode exception users list must be verified. | While a host is in lockdown mode (strict or normal), only users on the "Exception Users" list are allowed access. These users do not lose their permissions when the host enters lockdown mode.... |
| V-258748 | Medium | The ESXi host must protect the confidentiality and integrity of transmitted information by isolating vMotion traffic. | While encrypted vMotion is available, vMotion traffic should still be sequestered from other traffic to further protect it from attack. This network must only be accessible to other ESXi hosts,... |
| V-258764 | Medium | The ESXi host Secure Shell (SSH) daemon must not permit tunnels. | OpenSSH has the ability to create network tunnels (layer 2 and layer 3) over an SSH connection. This function can provide similar convenience to a virtual private network (VPN) with the similar... |
| V-258767 | Medium | The ESXi host must disable Simple Network Management Protocol (SNMP) v1 and v2c. | If SNMP is not being used, it must remain disabled. If it is being used, the proper trap destination must be configured. If SNMP is not properly configured, monitoring information can be sent to a... |
| V-258743 | Medium | The ESXi host must allocate audit record storage capacity to store at least one week's worth of audit records. | In order to ensure ESXi has sufficient storage capacity in which to write the audit logs, audit record storage capacity should be configured.
If a central audit record storage facility is... |
| V-258742 | Medium | The ESXi host must enforce an unlock timeout of 15 minutes after a user account is locked out. | By enforcing a reasonable unlock timeout after multiple failed logon attempts, the risk of unauthorized access via user password guessing, otherwise known as brute forcing, is reduced. Users must... |
| V-258741 | Medium | The ESXi host must enable Secure Boot. | Secure Boot is part of the Unified Extensible Firmware Interface (UEFI) firmware standard. With UEFI Secure Boot enabled, a host refuses to load any UEFI driver or app unless the operating system... |
| V-258740 | Medium | The ESXi host must implement Secure Boot enforcement. | Secure Boot is part of the UEFI firmware standard. With UEFI Secure Boot enabled, a host refuses to load any UEFI driver or app unless the operating system bootloader has a valid digital... |
| V-258747 | Medium | The ESXi host must enable bidirectional Challenge-Handshake Authentication Protocol (CHAP) authentication for Internet Small Computer Systems Interface (iSCSI) traffic. | When enabled, vSphere performs bidirectional authentication of both the iSCSI target and host. When not authenticating both the iSCSI target and host, there is potential for a man-in-the-middle... |
| V-258745 | Medium | The ESXi host must synchronize internal information system clocks to an authoritative time source. | To ensure the accuracy of the system clock, it must be synchronized with an authoritative time source within DOD. Many system functions, including time-based logon and activity restrictions,... |
| V-258744 | Medium | The ESXi host must offload logs via syslog. | Remote logging to a central log host provides a secure, centralized store for ESXi logs. By gathering host log files onto a central host, it can more easily monitor all hosts with a single tool.... |
| V-258734 | Medium | The ESXi host must enforce password complexity by configuring a password quality policy. | To enforce the use of complex passwords, minimum numbers of characters of different classes are mandated.
The use of complex passwords reduces the ability of attackers to successfully obtain... |
| V-258798 | Medium | The ESXi host must enforce the exclusive running of executables from approved VIBs. | The "execInstalledOnly" advanced ESXi boot option, when set to TRUE, guarantees that the VMkernel executes only those binaries that have been packaged as part of a signed VIB. While this option is... |
| V-258799 | Medium | The ESXi host must use sufficient entropy for cryptographic operations. | Starting in vSphere 8.0, the ESXi Entropy implementation supports the FIPS 140-3 and EAL4 certifications. Kernel boot options control which entropy sources to activate on an ESXi host.
In... |
| V-258755 | Medium | The ESXi host must be configured to disable nonessential capabilities by disabling the ESXi shell. | The ESXi Shell is an interactive command line environment available locally from the Direct Console User Interface (DCUI) or remotely via SSH. Activities performed from the ESXi Shell bypass... |
| V-258794 | Medium | The ESXi host must configure the firewall to restrict access to services running on the host. | Unrestricted access to services running on an ESXi host can expose a host to outside attacks and unauthorized access. Reduce the risk by configuring the ESXi firewall to only allow access from... |
| V-258795 | Medium | The ESXi host when using Host Profiles and/or Auto Deploy must use the vSphere Authentication Proxy to protect passwords when adding themselves to Active Directory. | If a host is configured to join an Active Directory domain using Host Profiles and/or Auto Deploy, the Active Directory credentials are saved in the profile and are transmitted over the... |
| V-258796 | Medium | The ESXi host must not use the default Active Directory ESX Admin group. | When adding ESXi hosts to Active Directory, all user/group accounts assigned to the Active Directory group "ESX Admins" will have full administrative access to the host.
If this group is not... |
| V-258797 | Medium | The ESXi host must configure a persistent log location for all locally stored logs. | ESXi can be configured to store log files on an in-memory file system. This occurs when the host's "/scratch" directory is linked to "/tmp/scratch". When this is done, only a single day's worth of... |
| V-258790 | Medium | The ESXi host must forward audit records containing information to establish what type of events occurred. | Without establishing what types of events occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack.
Audit record content that may be... |
| V-258792 | Medium | The ESXi host must not be configured to override virtual machine (VM) logger settings. | Each VM on an ESXi host runs in its own "vmx" process. Upon creation, a vmx process will look in two locations for configuration items, the ESXi host itself and the per-vm *.vmx file in the VM... |
| V-258793 | Medium | The ESXi host must require TPM-based configuration encryption. | An ESXi host's configuration consists of configuration files for each service that runs on the host. The configuration files typically reside in the /etc/ directory, but they can also reside in... |
| V-258738 | Medium | The ESXi host Secure Shell (SSH) daemon must ignore .rhosts files. | SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts. SSH can emulate the behavior of the obsolete "rsh" command in allowing users to enable... |
| V-258762 | Medium | The ESXi host Secure Shell (SSH) daemon must not permit user environment settings. | SSH environment options potentially allow users to bypass access restriction in some configurations. Users must not be able to present environment options to the SSH daemon. |
| V-258733 | Medium | The ESXi must produce audit records containing information to establish what type of events occurred. | Without establishing what types of events occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack.
Satisfies:... |
| V-258730 | Medium | The ESXi host must enable lockdown mode. | Enabling Lockdown Mode disables direct access to an ESXi host, requiring the host to be managed remotely from vCenter Server. This is done to ensure the roles and access controls implemented in... |
| V-258731 | Medium | The ESXi host client must be configured with an idle session timeout. | The ESXi host client is the UI served up by the host itself, outside of vCenter. It is accessed at https://<ESX FQDN>/ui. ESXi is not usually administered via this interface for long periods, and... |
| V-258736 | Medium | The ESXi host must be configured to disable nonessential capabilities by disabling the Managed Object Browser (MOB). | The MOB provides a way to explore the object model used by the VMkernel to manage the host and enables configurations to be changed. This interface is meant to be used primarily for debugging the... |
| V-258791 | Medium | The ESXi host must not be configured to override virtual machine (VM) configurations. | Each VM on an ESXi host runs in its own "vmx" process. Upon creation, a vmx process will look in two locations for configuration items, the ESXi host itself and the per-vm *.vmx file in the VM... |
| V-258735 | Medium | The ESXi host must prohibit password reuse for a minimum of five generations. | If a user or root used the same password continuously or was allowed to change it back shortly after being forced to change it to something else, it would provide a potential intruder with the... |
| V-258758 | Medium | The ESXi host must protect the confidentiality and integrity of transmitted information by isolating ESXi management traffic. | The vSphere management network provides access to the vSphere management interface on each component. Services running on the management interface provide an opportunity for an attacker to gain... |
| V-258759 | Medium | The ESXi host must protect the confidentiality and integrity of transmitted information by isolating IP-based storage traffic. | Virtual machines (VMs) might share virtual switches and VLANs with the IP-based storage configurations. IP-based storage includes vSAN, iSCSI, and NFS. This configuration might expose IP-based... |
| V-258756 | Medium | The ESXi host must automatically stop shell services after 10 minutes. | When the ESXi Shell or Secure Shell (SSH) services are enabled on a host, they will run indefinitely. To avoid having these services left running, set the "ESXiShellTimeOut". The... |
| V-258778 | Medium | The ESXi host must not suppress warnings about unmitigated hyperthreading vulnerabilities. | The L1 Terminal Fault (L1TF) CPU vulnerabilities published in 2018 have patches and mitigations available in vSphere. However, there are performance impacts to these mitigations that require... |
| V-258779 | Medium | The ESXi host must verify certificates for SSL syslog endpoints. | When sending syslog data to a remote host, ESXi can be configured to use any combination of TCP, UDP, and SSL transports. When using SSL, the server certificate must be validated to ensure that... |
| V-258751 | Medium | The ESXi host DCUI.Access list must be verified. | Lockdown mode disables direct host access, requiring that administrators manage hosts from vCenter Server. However, if a host becomes isolated from vCenter, the administrator is locked out and can... |
| V-258752 | Medium | The ESXi host must display the Standard Mandatory DOD Notice and Consent Banner before granting access to the system via Secure Shell (SSH). | Display of a standardized and approved use notification before granting access to the host ensures privacy and security notification verbiage used is consistent with applicable federal laws,... |
| V-258775 | Medium | The ESXi host must restrict the use of Virtual Guest Tagging (VGT) on standard switches. | When a port group is set to VLAN 4095, the vSwitch passes all network frames to the attached virtual machines (VMs) without modifying the VLAN tags. In vSphere, this is referred to as VGT. The VM... |
| V-258773 | Medium | The ESXi host must configure virtual switch security policies to reject promiscuous mode requests. | When promiscuous mode is enabled for a virtual switch, all virtual machines (VMs) connected to the Portgroup have the potential to read all packets across that network (only the virtual machines... |
| V-258770 | Medium | The ESXi host must enable Bridge Protocol Data Units (BPDU) filter on the host to prevent being locked out of physical switch ports with Portfast and BPDU Guard enabled. | BPDU Guard and Portfast are commonly enabled on the physical switch to which the ESXi host is directly connected to reduce the Spanning Tree Protocol (STP) convergence delay.
If a BPDU packet is... |
| V-258771 | Medium | The ESXi host must configure virtual switch security policies to reject forged transmits. | If the virtual machine (VM) operating system changes the Media Access Control (MAC) address, the operating system can send frames with an impersonated source MAC address at any time. This allows... |
| V-258750 | Medium | The ESXi host Secure Shell (SSH) daemon must be configured to only use FIPS 140-2 validated ciphers. | Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. ESXi must implement cryptographic modules adhering to the higher standards approved... |
| V-258739 | Medium | The ESXi host must set a timeout to automatically end idle shell sessions after fifteen minutes. | If a user forgets to log out of their local or remote ESXi Shell session, the idle connection will remain open indefinitely and increase the likelihood of inappropriate host access via session... |
| V-258777 | Medium | The ESXi host must not suppress warnings that the local or remote shell sessions are enabled. | Warnings that local or remote shell sessions are enabled alert administrators to activity they may not be aware of and need to investigate. |
| V-265974 | Medium | The ESXi host must use DOD-approved encryption to protect the confidentiality of network sessions. | Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session. In ESXi 8.0 Update 3 and newer TLS profiles are... |
| V-258774 | Medium | The ESXi host must restrict use of the dvFilter network application programming interface (API). | If the organization is not using products that use the dvFilter network API, the host should not be configured to send network information to a virtual machine (VM).
If the API is enabled, an... |
| V-265975 | Medium | The ESXi host must disable key persistence. | When using a standard key provider, the ESXi host relies on vCenter Server to manage the encryption keys. When using a trusted key provider, the ESXi host relies directly on the Trust Authority... |
| V-258768 | Low | The ESXi host must disable Inter-Virtual Machine (VM) Transparent Page Sharing. | Published academic papers have demonstrated that by forcing a flush and reload of cache memory, it is possible to measure memory timings to try to determine an Advanced Encryption Standard (AES)... |
| V-258765 | Low | The ESXi host Secure Shell (SSH) daemon must set a timeout count on idle sessions. | Setting a timeout ensures that a user login will be terminated as soon as the "ClientAliveCountMax" is reached. |
| V-258766 | Low | The ESXi host Secure Shell (SSH) daemon must set a timeout interval on idle sessions. | Automatically logging out idle users guards against compromises via hijacked administrative sessions. |
| V-258763 | Low | The ESXi host Secure Shell (SSH) daemon must be configured to not allow gateway ports. | SSH Transmission Control Protocol (TCP) connection forwarding provides a mechanism to establish TCP connections proxied by the SSH server. This function can provide convenience similar to a... |
| V-258737 | Low | The ESXi host must uniquely identify and must authenticate organizational users by using Active Directory. | Join ESXi hosts to an Active Directory domain to eliminate the need to create and maintain multiple local user accounts. Using Active Directory for user authentication simplifies the ESXi host... |
