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Objective ID
Severity
Discussion
V-239258
medium
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 vCenter are always enforced and users cannot bypass them by logging on to a host directly. By forcing all interaction to occur through vCenter Server, the risk of someone inadvertently attaining elevated privileges or performing tasks that are not properly audited is greatly reduced.
Satisfies: SRG-OS-000027-VMM-000080, SRG-OS-000123-VMM-000620
Satisfies: SRG-OS-000027-VMM-000080, SRG-OS-000123-VMM-000620
V-239259
low
Lockdown mode disables direct host access, requiring that administrators manage hosts from vCenter Server. However, if a host becomes isolated from vCenter Server, the administrator is locked out and can no longer manage the host. If using normal Lockdown Mode, avoid becoming locked out of an ESXi host that is running in Lockdown Mode by setting DCUI.Access to a list of highly trusted users who can override Lockdown Mode and access the DCUI. The DCUI is not running in strict Lockdown Mode.
V-239260
low
In vSphere, users can be added to the Exception Users list from the vSphere Web Client. These users do not lose their permissions when the host enters Lockdown Mode.
Before adding service accounts such as a backup agent to the Exception Users list, verify that the list of users who are exempted from losing permissions is legitimate and as needed per the environment. Users who do not require special permissions should not be exempted from Lockdown Mode.
Before adding service accounts such as a backup agent to the Exception Users list, verify that the list of users who are exempted from losing permissions is legitimate and as needed per the environment. Users who do not require special permissions should not be exempted from Lockdown Mode.
V-239261
medium
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. It can also do aggregate analysis and searching to look for such things as coordinated attacks on multiple hosts. Logging to a secure, centralized log server also helps prevent log tampering and also provides a long-term audit record.
Satisfies: SRG-OS-000032-VMM-000130, SRG-OS-000342-VMM-001230, SRG-OS-000479-VMM-001990
Satisfies: SRG-OS-000032-VMM-000130, SRG-OS-000342-VMM-001230, SRG-OS-000479-VMM-001990
V-239262
medium
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 reached, the account is locked by the ESXi host.
V-239263
medium
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 wait for the timeout period to elapse before subsequent logon attempts are allowed.
V-239264
medium
Failure to display the DoD logon banner prior to a logon attempt will negate legal proceedings resulting from unauthorized access to system resources.
Satisfies: SRG-OS-000023-VMM-000060, SRG-OS-000024-VMM-000070
Satisfies: SRG-OS-000023-VMM-000060, SRG-OS-000024-VMM-000070
V-239265
medium
Failure to display the DoD logon banner prior to a logon attempt will negate legal proceedings resulting from unauthorized access to system resources.
V-239266
medium
The warning message reinforces policy awareness during the logon process and facilitates possible legal action against attackers. Alternatively, systems whose ownership should not be obvious should ensure usage of a banner that does not provide easy attribution.
V-239267
medium
Approved algorithms should impart some level of confidence in their implementation. Limit the ciphers to algorithms that are FIPS approved. Counter (CTR) mode is also preferred over cipher-block chaining (CBC) mode.
V-239268
medium
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 insecure access to their accounts via ".rhosts" files.
V-239269
medium
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" authentication, since hosts are cryptographically authenticated. However, it is not recommended that hosts unilaterally trust one another, even within an organization.
V-239270
low
Permitting direct root login reduces auditable information about who ran privileged commands on the system and also allows direct attack attempts on root's password.
V-239271
high
Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere.
V-239272
medium
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-239273
low
GSSAPI authentication is used to provide additional authentication mechanisms to applications. Allowing GSSAPI authentication through SSH exposes the system’s GSSAPI to remote hosts, increasing the attack surface of the system.
V-239274
low
Kerberos authentication for SSH is often implemented using GSSAPI. If Kerberos is enabled through SSH, the SSH daemon provides a means of access to the system's Kerberos implementation. Vulnerabilities in the system's Kerberos implementation may then be subject to exploitation. To reduce the attack surface of the system, the Kerberos authentication mechanism within SSH must be disabled for systems.
V-239275
medium
If other users have access to modify user-specific SSH configuration files, they may be able to log on to the system as another user.
V-239276
medium
If compression is allowed in an SSH connection prior to authentication, vulnerabilities in the compression software could result in compromise of the system from an unauthenticated connection, potentially with root privileges.
V-239277
low
SSH TCP connection forwarding provides a mechanism to establish TCP connections proxied by the SSH server. This function can provide similar convenience to a Virtual Private Network (VPN) with the similar risk of providing a path to circumvent firewalls and network Access Control Lists (ACLs). Gateway ports allow remote forwarded ports to bind to non-loopback addresses on the server.
V-239278
medium
X11 forwarding over SSH allows for the secure remote execution of X11-based applications. This feature can increase the attack surface of an SSH connection.
V-239279
medium
Environment variables can be used to change the behavior of remote sessions and should be limited. Locale environment variables specify the language, character set, and other features modifying the operation of software to match the user's preferences.
V-239280
medium
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 risk of providing a path to circumvent firewalls and network Access Control Lists (ACLs).
V-239281
low
Setting a timeout ensures that a user login will be terminated as soon as the "ClientAliveCountMax" is reached.
V-239282
low
Automatically logging out idle users guards against compromises via hijacked administrative sessions.
V-239283
medium
The SSH protocol has the ability to provide multiple sessions over a single connection without reauthentication. A compromised client could use this feature to establish additional sessions to a system without consent or knowledge of the user.
V-239284
medium
ESXi hosts come with SSH, which can be enabled to allow remote access without requiring user authentication. To enable password-free access, copy the remote user's public key into the "/etc/ssh/keys-root/authorized_keys" file on the ESXi host.
The presence of the remote user's public key in the "authorized_keys" file identifies the user as trusted, meaning the user is granted access to the host without providing a password.
If using Lockdown Mode and SSH is disabled, then logon with authorized keys will have the same restrictions as username/password.
The presence of the remote user's public key in the "authorized_keys" file identifies the user as trusted, meaning the user is granted access to the host without providing a password.
If using Lockdown Mode and SSH is disabled, then logon with authorized keys will have the same restrictions as username/password.
V-239285
low
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: SRG-OS-000037-VMM-000150, SRG-OS-000063-VMM-000310
Satisfies: SRG-OS-000037-VMM-000150, SRG-OS-000063-VMM-000310
V-239286
medium
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 valid passwords using guessing or exhaustive search techniques. Complexity requirements increase the password search space by requiring users to construct passwords from a larger character set than they may otherwise use.
Satisfies: SRG-OS-000069-VMM-000360, SRG-OS-000070-VMM-000370, SRG-OS-000071-VMM-000380, SRG-OS-000078-VMM-000450, SRG-OS-000072-VMM-000390, SRG-OS-000266-VMM-000940
Satisfies: SRG-OS-000069-VMM-000360, SRG-OS-000070-VMM-000370, SRG-OS-000071-VMM-000380, SRG-OS-000078-VMM-000450, SRG-OS-000072-VMM-000390, SRG-OS-000266-VMM-000940
V-239287
medium
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 opportunity to keep guessing at one user's password until it was guessed correctly.
V-239288
medium
Systems must employ cryptographic hashes for passwords using the SHA-2 family of algorithms or FIPS 140-2 approved successors. The use of unapproved algorithms may result in weak password hashes more vulnerable to compromise.
V-239289
medium
The MOB provides a way to explore the object model used by the VMkernel to manage the host and enables configurations to be changed as well. This interface is meant to be used primarily for debugging the vSphere SDK, but because there are no access controls it could also be used as a method to obtain information about a host being targeted for unauthorized access.
V-239290
medium
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 primarily for use in break-fix scenarios, the ESXi shell is well suited for checking and modifying configuration details, not always generally accessible, using the vSphere Client.
The ESXi shell is accessible remotely using SSH by users with the Administrator role. Under normal operating conditions, SSH access to the host must be disabled as is the default. As with the ESXi shell, SSH is also intended only for temporary use during break-fix scenarios. SSH must therefore be disabled under normal operating conditions and must only be enabled for diagnostics or troubleshooting. Remote access to the host must therefore be limited to the vSphere Client or Host Client at all other times.
Satisfies: SRG-OS-000095-VMM-000480, SRG-OS-000297-VMM-001040, SRG-OS-000298-VMM-001050
The ESXi shell is accessible remotely using SSH by users with the Administrator role. Under normal operating conditions, SSH access to the host must be disabled as is the default. As with the ESXi shell, SSH is also intended only for temporary use during break-fix scenarios. SSH must therefore be disabled under normal operating conditions and must only be enabled for diagnostics or troubleshooting. Remote access to the host must therefore be limited to the vSphere Client or Host Client at all other times.
Satisfies: SRG-OS-000095-VMM-000480, SRG-OS-000297-VMM-001040, SRG-OS-000298-VMM-001050
V-239291
medium
The ESXi Shell is an interactive command line environment available locally from the DCUI or remotely via SSH. Activities performed from the ESXi Shell bypass vCenter RBAC and audit controls.
The ESXi shell should only be turned on when needed to troubleshoot/resolve problems that cannot be fixed through the vSphere client.
The ESXi shell should only be turned on when needed to troubleshoot/resolve problems that cannot be fixed through the vSphere client.
V-239292
low
Join ESXi hosts to an Active Directory (AD) domain to eliminate the need to create and maintain multiple local user accounts. Using AD for user authentication simplifies the ESXi host configuration, ensures password complexity and reuse policies are enforced, and reduces the risk of security breaches and unauthorized access.
Note: If the AD group "ESX Admins" (default) exists, then all users and groups that are assigned as members to this group will have full administrative access to all ESXi hosts the domain.
Satisfies: SRG-OS-000104-VMM-000500, SRG-OS-000109-VMM-000550, SRG-OS-000112-VMM-000560, SRG-OS-000113-VMM-000570
Note: If the AD group "ESX Admins" (default) exists, then all users and groups that are assigned as members to this group will have full administrative access to all ESXi hosts the domain.
Satisfies: SRG-OS-000104-VMM-000500, SRG-OS-000109-VMM-000550, SRG-OS-000112-VMM-000560, SRG-OS-000113-VMM-000570
V-239293
medium
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 network. To avoid having to save Active Directory credentials in the Host Profile and to avoid transmitting Active Directory credentials over the network, use the vSphere Authentication Proxy.
Satisfies: SRG-OS-000104-VMM-000500, SRG-OS-000109-VMM-000550, SRG-OS-000112-VMM-000560, SRG-OS-000113-VMM-000570
Satisfies: SRG-OS-000104-VMM-000500, SRG-OS-000109-VMM-000550, SRG-OS-000112-VMM-000560, SRG-OS-000113-VMM-000570
V-239294
low
When adding ESXi hosts to Active Directory (AD), all user/group accounts assigned to the AD group "ESX Admins" will have full administrative access to the host. If this group is not controlled or known to the System Administrators, it may be used for inappropriate access to the host. Therefore, the default group must be changed to a site-specific AD group and membership therein must be severely restricted.
Satisfies: SRG-OS-000104-VMM-000500, SRG-OS-000109-VMM-000550, SRG-OS-000112-VMM-000560, SRG-OS-000113-VMM-000570
Satisfies: SRG-OS-000104-VMM-000500, SRG-OS-000109-VMM-000550, SRG-OS-000112-VMM-000560, SRG-OS-000113-VMM-000570
V-239295
low
To ensure accountability and prevent unauthenticated access, privileged users must utilize multifactor authentication to prevent potential misuse and compromise of the system.
Note: This feature requires an existing PKI and AD integration.
Satisfies: SRG-OS-000107-VMM-000530, SRG-OS-000376-VMM-001520, SRG-OS-000377-VMM-001530, SRG-OS-000403-VMM-001640
Note: This feature requires an existing PKI and AD integration.
Satisfies: SRG-OS-000107-VMM-000530, SRG-OS-000376-VMM-001520, SRG-OS-000377-VMM-001530, SRG-OS-000403-VMM-001640
V-239296
medium
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 hijacking. The "ESXiShellInteractiveTimeOut" allows the automatic termination of idle shell sessions.
Satisfies: SRG-OS-000163-VMM-000700, SRG-OS-000279-VMM-001010
Satisfies: SRG-OS-000163-VMM-000700, SRG-OS-000279-VMM-001010
V-239297
medium
When the ESXi Shell or SSH services are enabled on a host, they will run indefinitely. To avoid having these services left running, set the "ESXiShellTimeOut". The "ESXiShellTimeOut" defines a window of time after which the ESXi Shell and SSH services will be stopped automatically.
Satisfies: SRG-OS-000163-VMM-000700, SRG-OS-000279-VMM-001010
Satisfies: SRG-OS-000163-VMM-000700, SRG-OS-000279-VMM-001010
V-239298
medium
When the direct console user interface (DCUI) is enabled and logged in, it should be automatically logged out if left logged in to avoid access by unauthorized persons. The "DcuiTimeOut" setting defines a window of time after which the DCUI will be logged out.
Satisfies: SRG-OS-000163-VMM-000700, SRG-OS-000279-VMM-001010
Satisfies: SRG-OS-000163-VMM-000700, SRG-OS-000279-VMM-001010
V-239299
low
In the event of a system failure, the system must preserve any information necessary to determine cause of failure and any information necessary to return to operations with least disruption to mission processes.
V-239300
medium
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 logs is stored at any time. In addition, log files will be reinitialized upon each reboot. This presents a security risk as user activity logged on the host is only stored temporarily and will not persist across reboots. This can also complicate auditing and make it harder to monitor events and diagnose issues. ESXi host logging should always be configured to a persistent datastore.
Note: Scratch space is configured automatically during installation or first boot of an ESXi host and does not usually need to be manually configured. ESXi Installable creates a 4 GB Fat16 partition on the target device during installation if there is sufficient space and if the device is considered "local".
If ESXi is installed on an SD card or USB device, a persistent log location may not be configured upon install as normal.
Note: Scratch space is configured automatically during installation or first boot of an ESXi host and does not usually need to be manually configured. ESXi Installable creates a 4 GB Fat16 partition on the target device during installation if there is sufficient space and if the device is considered "local".
If ESXi is installed on an SD card or USB device, a persistent log location may not be configured upon install as normal.
V-239301
medium
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, automated reports, system logs, and audit records, depend on an accurate system clock. If there is no confidence in the correctness of the system clock, time-based functions may not operate as intended and records may be of diminished value.
Satisfies: SRG-OS-000355-VMM-001330, SRG-OS-000356-VMM-001340
Satisfies: SRG-OS-000355-VMM-001330, SRG-OS-000356-VMM-001340
V-239302
high
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. VMwareCertified - VIBs created, tested, and signed by VMware
2. VMwareAccepted - VIBs created by a VMware partner but tested and signed by VMware
3. PartnerSupported - VIBs created, tested, and signed by a certified VMware partner
4. CommunitySupported - VIBs that have not been tested by VMware or a VMware partner
CommunitySupported VIBs are not supported and do not have a digital signature. To protect the security and integrity of ESXi hosts, do not allow unsigned (CommunitySupported) VIBs to be installed on hosts.
Satisfies: SRG-OS-000366-VMM-001430, SRG-OS-000370-VMM-001460, SRG-OS-000404-VMM-001650
1. VMwareCertified - VIBs created, tested, and signed by VMware
2. VMwareAccepted - VIBs created by a VMware partner but tested and signed by VMware
3. PartnerSupported - VIBs created, tested, and signed by a certified VMware partner
4. CommunitySupported - VIBs that have not been tested by VMware or a VMware partner
CommunitySupported VIBs are not supported and do not have a digital signature. To protect the security and integrity of ESXi hosts, do not allow unsigned (CommunitySupported) VIBs to be installed on hosts.
Satisfies: SRG-OS-000366-VMM-001430, SRG-OS-000370-VMM-001460, SRG-OS-000404-VMM-001650
V-239303
medium
While encrypted vMotion is available now, vMotion traffic should still be sequestered from other traffic to further protect it from attack. This network must be only be accessible to other ESXi hosts preventing outside access to the network.
V-239304
medium
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 privileged access to the systems. Any remote attack most likely would begin with gaining entry to this network.
V-239305
medium
Virtual machines 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 storage traffic to unauthorized virtual machine users. IP-based storage frequently is not encrypted. It can be viewed by anyone with access to this network.
To restrict unauthorized users from viewing the IP-based storage traffic, the IP-based storage network must be logically separated from the production traffic. Configuring the IP-based storage adaptors on separate VLANs or network segments from other VMkernels and virtual machines will limit unauthorized users from viewing the traffic.
To restrict unauthorized users from viewing the IP-based storage traffic, the IP-based storage network must be logically separated from the production traffic. Configuring the IP-based storage adaptors on separate VLANs or network segments from other VMkernels and virtual machines will limit unauthorized users from viewing the traffic.
V-239306
low
Three different TCP/IP stacks are available by default on ESXi: Default, Provisioning, and vMotion.
To better protect and isolate sensitive network traffic within ESXi, administrators must configure each of these stacks. Additional custom TCP/IP stacks can be created if desired.
To better protect and isolate sensitive network traffic within ESXi, administrators must configure each of these stacks. Additional custom TCP/IP stacks can be created if desired.
V-239307
medium
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 malicious host that can then use this information to plan an attack.
V-239308
low
When enabled, vSphere performs bidirectional authentication of both the iSCSI target and host. There is a potential for a MiTM attack, when not authenticating both the iSCSI target and host, in which an attacker might impersonate either side of the connection to steal data. Bidirectional authentication mitigates this risk.
V-239309
low
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 AES encryption key in use on another virtual machine running on the same physical processor of the host server if Transparent Page Sharing is enabled between the two virtual machines. This technique works only in a highly controlled system configured in a non-standard way that VMware believes would not be recreated in a production environment.
Although VMware believes information being disclosed in real-world conditions is unrealistic, out of an abundance of caution, upcoming ESXi update releases will no longer enable TPS between virtual machines by default (TPS will still be used within individual VMs).
Although VMware believes information being disclosed in real-world conditions is unrealistic, out of an abundance of caution, upcoming ESXi update releases will no longer enable TPS between virtual machines by default (TPS will still be used within individual VMs).
V-239310
medium
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 authorized networks.
V-239311
medium
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 making sure this is set to deny incoming and outgoing traffic.
V-239312
low
BPDU Guard and Portfast are commonly enabled on the physical switch to which the ESXi host is directly connected to reduce the STP convergence delay.
If a BPDU packet is sent from a virtual machine on the ESXi host to the physical switch so configured, a cascading lockout of all the uplink interfaces from the ESXi host can occur. To prevent this type of lockout, BPDU Filter can be enabled on the ESXi host to drop any BPDU packets being sent to the physical switch.
The caveat is that certain SSL VPNs that use Windows bridging capability can legitimately generate BPDU packets. The administrator should verify that there are no legitimate BPDU packets generated by virtual machines on the ESXi host prior to enabling BPDU Filter. If BPDU Filter is enabled in this situation, enabling Reject Forged Transmits on the virtual switch port group adds protection against Spanning Tree loops.
If a BPDU packet is sent from a virtual machine on the ESXi host to the physical switch so configured, a cascading lockout of all the uplink interfaces from the ESXi host can occur. To prevent this type of lockout, BPDU Filter can be enabled on the ESXi host to drop any BPDU packets being sent to the physical switch.
The caveat is that certain SSL VPNs that use Windows bridging capability can legitimately generate BPDU packets. The administrator should verify that there are no legitimate BPDU packets generated by virtual machines on the ESXi host prior to enabling BPDU Filter. If BPDU Filter is enabled in this situation, enabling Reject Forged Transmits on the virtual switch port group adds protection against Spanning Tree loops.
V-239313
medium
If the virtual machine operating system changes the MAC address, the operating system can send frames with an impersonated source MAC address at any time. This allows an operating system to stage malicious attacks on the devices in a network by impersonating a network adaptor authorized by the receiving network.
This means the virtual switch does not compare the source and effective MAC addresses.
To protect against MAC address impersonation, all virtual switches should have forged transmissions set to reject. Reject Forged Transmit can be set at the vSwitch and/or the Portgroup level. Switch-level settings can be overridden at the Portgroup level.
This means the virtual switch does not compare the source and effective MAC addresses.
To protect against MAC address impersonation, all virtual switches should have forged transmissions set to reject. Reject Forged Transmit can be set at the vSwitch and/or the Portgroup level. Switch-level settings can be overridden at the Portgroup level.
V-239314
high
If the virtual machine 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 devices in a network by impersonating a network adaptor authorized by the receiving network.
This will prevent VMs from changing their effective MAC address. It will affect applications that require this functionality, how a layer 2 bridge will operate, and applications that require a specific MAC address for licensing. Reject MAC Changes can be set at the vSwitch and/or the Portgroup level. Switch-level settings can be overridden at the Portgroup level.
This will prevent VMs from changing their effective MAC address. It will affect applications that require this functionality, how a layer 2 bridge will operate, and applications that require a specific MAC address for licensing. Reject MAC Changes can be set at the vSwitch and/or the Portgroup level. Switch-level settings can be overridden at the Portgroup level.
V-239315
medium
When Promiscuous Mode is enabled for a virtual switch, all virtual machines connected to the Portgroup have the potential of reading all packets across that network, meaning only the virtual machines connected to that Portgroup.
Promiscuous Mode is disabled by default on the ESXi Server, and this is the recommended setting. Promiscuous Mode can be set at the vSwitch and/or the Portgroup level. Switch-level settings can be overridden at the Portgroup level.
Promiscuous Mode is disabled by default on the ESXi Server, and this is the recommended setting. Promiscuous Mode can be set at the vSwitch and/or the Portgroup level. Switch-level settings can be overridden at the Portgroup level.
V-239316
medium
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 VM.
If the API is enabled, an attacker might attempt to connect a VM to it, potentially providing access to the network of other VMs on the host. If the organization is using a product that uses this API, verify that the host has been configured correctly. If the organization is not using such a product, ensure the setting is blank.
If the API is enabled, an attacker might attempt to connect a VM to it, potentially providing access to the network of other VMs on the host. If the organization is using a product that uses this API, verify that the host has been configured correctly. If the organization is not using such a product, ensure the setting is blank.
V-239317
medium
ESXi does not use the concept of native VLAN. Frames with VLAN specified in the port group will have a tag, but frames with VLAN not specified in the port group are not tagged and therefore will end up as belonging to the native VLAN of the physical switch.
For example, frames on VLAN 1 from a Cisco physical switch will be untagged, because this is considered as the native VLAN. However, frames from ESXi specified as VLAN 1 will be tagged with a "1"; therefore, traffic from ESXi that is destined for the native VLAN will not be correctly routed (because it is tagged with a "1" instead of being untagged), and traffic from the physical switch coming from the native VLAN will not be visible (because it is not tagged).
If the ESXi virtual switch port group uses the native VLAN ID, traffic from those VMs will not be visible to the native VLAN on the switch because the switch is expecting untagged traffic.
For example, frames on VLAN 1 from a Cisco physical switch will be untagged, because this is considered as the native VLAN. However, frames from ESXi specified as VLAN 1 will be tagged with a "1"; therefore, traffic from ESXi that is destined for the native VLAN will not be correctly routed (because it is tagged with a "1" instead of being untagged), and traffic from the physical switch coming from the native VLAN will not be visible (because it is not tagged).
If the ESXi virtual switch port group uses the native VLAN ID, traffic from those VMs will not be visible to the native VLAN on the switch because the switch is expecting untagged traffic.
V-239318
medium
When a port group is set to VLAN 4095, this activates VGT mode. In this mode, the vSwitch passes all network frames to the guest VM without modifying the VLAN tags, leaving it up to the guest to deal with them. VLAN 4095 should be used only if the guest has been specifically configured to manage VLAN tags itself. If VGT is enabled inappropriately, it might cause denial of service or allow a guest VM to interact with traffic on an unauthorized VLAN.
V-239319
medium
Certain physical switches reserve certain VLAN IDs for internal purposes and often disallow traffic configured to these values. For example, Cisco Catalyst switches typically reserve VLANs 1001-1024 and 4094, while Nexus switches typically reserve 3968-4047 and 4094. Check the documentation for the specific switch. Using a reserved VLAN might result in a denial of service on the network.
V-239320
medium
To communicate with virtual switches in VST mode, external switch ports must be configured as trunk ports. VST mode does not support Dynamic Trunking Protocol (DTP), so the trunk must be static and unconditional. The auto or desirable physical switch settings do not work with the ESXi Server because the physical switch communicates with the ESXi Server using DTP.
The non-negotiate and on options unconditionally enable VLAN trunking on the physical switch and create a VLAN trunk link between the ESXi Server and the physical switch. The difference between non-negotiate and on options is that on mode still sends out DTP frames, whereas the non-negotiate option does not. The non-negotiate option should be used for all VLAN trunks to minimize unnecessary network traffic for virtual switches in VST mode.
The non-negotiate and on options unconditionally enable VLAN trunking on the physical switch and create a VLAN trunk link between the ESXi Server and the physical switch. The difference between non-negotiate and on options is that on mode still sends out DTP frames, whereas the non-negotiate option does not. The non-negotiate option should be used for all VLAN trunks to minimize unnecessary network traffic for virtual switches in VST mode.
V-239321
low
Since VMware virtual switches do not support STP, the ESXi host-connected physical switch ports must have portfast configured if spanning tree is enabled to avoid loops within the physical switch network. If these are not set, potential performance and connectivity issues might arise.
V-239322
medium
When defining a physical switch port for trunk mode, only specified VLANs must be configured on the VLAN trunk link. The risk with not fully documenting all VLANs on the vSwitch is that it is possible that a physical trunk port might be configured without needed VLANs, or with unneeded VLANs. This could enable an administrator to either accidentally or maliciously connect a VM to an unauthorized VLAN.
V-239323
medium
The CIM system provides an interface that enables hardware-level management from remote applications via a set of standard APIs. Create a limited-privilege, read-only service account for CIM. Grant this role to the user on the ESXi server. Place this user in the Exception Users list. When/where write access is required, create/enable a limited-privilege service account and grant only the minimum required privileges.
V-239324
high
Always check the SHA1 or MD5 hash after downloading an ISO, offline bundle, or patch to ensure integrity and authenticity of the downloaded files.
V-239325
high
Installing software updates is a fundamental mitigation against the exploitation of publicly known vulnerabilities.
V-239326
high
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 supported.
Mandating TLS 1.2 may break third-party integrations and add-ons to vSphere. Test these integrations carefully after implementing TLS 1.2 and roll back where appropriate.
On interfaces where required functionality is broken with TLS 1.2 this finding is not applicable until the third-party software supports TLS 1.2.
Be sure to modify TLS settings in the following order:
1. Platform Services Controllers (if applicable)
2. vCenter
3. ESXi
Mandating TLS 1.2 may break third-party integrations and add-ons to vSphere. Test these integrations carefully after implementing TLS 1.2 and roll back where appropriate.
On interfaces where required functionality is broken with TLS 1.2 this finding is not applicable until the third-party software supports TLS 1.2.
Be sure to modify TLS settings in the following order:
1. Platform Services Controllers (if applicable)
2. vCenter
3. ESXi
V-239327
medium
Secure Boot is a protocol of UEFI firmware that ensures the integrity of the boot process from hardware up through to the OS. Secure Boot for ESXi requires support from the firmware and requires that all ESXi kernel modules, drivers, and vSphere Installation Bundles (VIBs) be signed by VMware or a partner subordinate.
V-239328
medium
The default self-signed, VMware Certificate Authority-issued host certificate must be replaced with a DoD-approved certificate when the host will be accessed directly, such as during a VM console connection.
The use of a DoD certificate on the host assures clients that the service they are connecting to is legitimate and properly secured.
The use of a DoD certificate on the host assures clients that the service they are connecting to is legitimate and properly secured.
V-239329
medium
Warnings that local or remote shell sessions are enabled alert administrators to activity that they may not be aware of and need to investigate.
V-239331
medium
Approved algorithms should impart some level of confidence in their implementation. These are also required for compliance.
V-257278
high
Security flaws with software applications are discovered daily. Vendors are constantly updating and patching their products to address newly discovered security vulnerabilities. Organizations (including any contractor to the organization) are required to promptly install security-relevant software updates (e.g., patches, service packs, and hot fixes). Flaws discovered during security assessments, continuous monitoring, incident response activities, or information system error handling must also be addressed expeditiously.
Organization-defined time periods for updating security-relevant software may vary based on a variety of factors including, for example, the security category of the information system or the criticality of the update (i.e., severity of the vulnerability related to the discovered flaw).
This requirement will apply to software patch management solutions that are used to install patches across the enclave and to applications that are not part of that patch management solution. For example, many browsers today provide the capability to install their own patch software. Patch criticality, as well as system criticality, will vary. Therefore, the tactical situations regarding the patch management process will also vary. This means the time period used must be a configurable parameter. Time frames for application of security-relevant software updates may be dependent upon the Information Assurance Vulnerability Management (IAVM) process.
The application will be configured to check for and install security-relevant software updates within an identified time period from the availability of the update. The specific time period will be defined by an authoritative source (e.g., IAVM, CTOs, DTMs, and STIGs).
Organization-defined time periods for updating security-relevant software may vary based on a variety of factors including, for example, the security category of the information system or the criticality of the update (i.e., severity of the vulnerability related to the discovered flaw).
This requirement will apply to software patch management solutions that are used to install patches across the enclave and to applications that are not part of that patch management solution. For example, many browsers today provide the capability to install their own patch software. Patch criticality, as well as system criticality, will vary. Therefore, the tactical situations regarding the patch management process will also vary. This means the time period used must be a configurable parameter. Time frames for application of security-relevant software updates may be dependent upon the Information Assurance Vulnerability Management (IAVM) process.
The application will be configured to check for and install security-relevant software updates within an identified time period from the availability of the update. The specific time period will be defined by an authoritative source (e.g., IAVM, CTOs, DTMs, and STIGs).