On the Windows operating system, service programs are run either using the SYSTEM login ID, which possesses almost every privilege on the system (and consequently can do the maximum harm) and which requires no password or using a named local or domain account. Services are run in the security context of a named account in order to reduce the privileges available to them at runtime.
When Windows services are run with a named account, the password for that account is needed to start the service process. This means that the Service Control Manager (SCM), IIS web server, Scheduler, etc. all need to know both the ID and password of service accounts, when they are configured to run jobs, services, application pools or similar contexts as a named account, rather than as SYSTEM.
Service account passwords differ from administrator passwords in that they appear in at least two places:
- Hashed, in the security database -- e.g., the local SAM database or Active Directory, just like any other account.
- Reversibly encrypted or plaintext, in the registry or a configuration file, where the program that starts the service (e.g., Service Control Manager, Scheduler, IIS, ...) can retrieve the password value when starting a new service process.
Some Windows components, notably IIS, are able to periodically change the passwords of local service accounts they use. Unfortunately, this capability does not extend to domain service accounts, used to run services on multiple systems and does not apply to all types of service accounts. This means that many Windows service account passwords remain static by default.
Hitachi ID Bravura Privilege can be configured to secure service account passwords. This means two things, depending on the mode of operation:
- In push mode (i.e., no local agent on the Windows server), Bravura Privilege servers periodically connect to Windows servers or Active Directory in order to change the passwords of service accounts.
- If the local workstation service is installed on a Windows system (i.e., the "pull mode" agent), the Bravura Privilege service periodically changes service account passwords locally, in coordination with the central Bravura Privilege server cluster.
In both cases, Bravura Privilege must notify the program that launches services -- the subscriber -- of the new password value, so that it can successfully launch the service at the time of the next system restart or when an administrator manually stops and restarts the service in question. In some cases, for example when domain accounts are used to run services, an immediate restart may be required or advisable, due to Kerberos token expiry. Bravura Privilege can be configured to restart services after each automated password change.
Bravura Privilege includes extensive automation to discover subscribers and subscriber-to-service-account dependency. This allows Hitachi ID Systems customers to review what services are run in the security context of what named users, on what systems. This is particularly helpful where services run in the security context of domain accounts, since multiple services on multiple servers may run as the same service account and may therefore require notification after each password change.
Bravura Privilege includes several mechanisms to accomplish safe and secure changes to service account passwords:
- Auto-discovery of subscriber/account dependencies for a variety of subscriber types: IIS (multiple sub-components may have service accounts/passwords), Scheduler, SCM, DCOM, at various OS and subscriber versions.
- White-list policy tables:
- Initialized with discovered data about service accounts and services.
- Allow organizations to specify a password randomization schedule.
- Allow organizations to name application owners, who will be notified of password changes and any issues.
- Allow organizations to specify a style of notification. For example, notify the subscriber of new password values before a password change, after or both? Restart the subscriber or not?
- A mechanism that tests for the availability of all subscribers before each password change. In particular, if some systems where services run in the security context of a domain service account are unreachable, then changes to that account's password will be deferred.
- Built-in tools to notify subscribers of new password values and restart services if this was specified in the policy.
- A transaction manager that will retry notifications to subscribers that went off-line after a password was changed and before they could be notified of the new password value.
The above are primarily used when managed systems are integrated with Bravura Privilege in "push mode" -- i.e., there is no locally installed agent on the target system and Bravura Privilege initiates all connections remotely, over the network, directly or via a Bravura Privilege proxy server deployed near the target system.
Where push mode is inappropriate -- for example because the relevant services (remote registry, WMI, etc.) are disabled or firewalled or because the end system is offline or inaccessible due to name resolution or IP routing issues (NAT, etc.), a local workstation service can be installed on the managed system, which performs essentially the same functions but with much simpler connectivity (call home over HTTPS) and no need for network accessible services on the local system.
The local workstation service is most often used on laptops and in firewalled network segments (DMZs).
Bravura Privilege is normally configured to contact application owners after each password change and in the event of a problem. This makes troubleshooting easier in the event that notification failed and a service subsequently could not be started.
The entire infrastructure mentioned here is extensible. Customers
can expand it to support other process-launching systems, such as
third job party schedulers for example.