Account management is concerned with the creation, management, disablement, and termination of accounts. If you’re planning to take the SY0-501 version of the Security+ exam, you should have a basic understanding of common account management practices.
For example, can you answer this question?
Q. A recent security audit discovered several apparently dormant user accounts. Although users could log on to the accounts, no one had logged on to them for more than 60 days. You later discovered that these accounts are for contractors who work approximately one week every quarter. Which of the following is the BEST response to this situation?
A. Remove the account expiration from the accounts.
B. Delete the accounts.
C. Reset the accounts.
D. Disable the accounts.
More, do you know why the correct answer is correct and the incorrect answers are incorrect? The answer and explanation are available at the end of this post.
Require Administrators to Use Two Accounts
It’s common to require administrators to have two accounts. They use one account for regular day-to-day work. It has the same limited privileges as a regular end user. The other account has elevated privileges required to perform administrative work, and they use this only when performing administrative work. The benefit of this practice is that it reduces the exposure of the administrative account to an attack.
For example, when malware infects a system, it often attempts to gain additional rights and permissions using privilege escalation techniques. It may exploit a bug or flaw in an application or operating system. Or, it may simply assume the rights and permissions of the logged-on user. If an administrator logs on with an administrative account, the malware can assume these elevated privileges. In contrast, if the administrator is logged on with a regular standard user account, the malware must take additional steps to escalate its privileges.
This also reduces the risk to the administrative account for day-to-day work. Imagine Homer is an administrator and he’s called away to a crisis. It is very possible for him to walk away without locking his computer. If he was logged on with his administrator account, an attacker walking by can access the system and have administrative privileges. Although systems often have password-protected screen savers, these usually don’t start until about 10 minutes or longer after a user walks away.
Prohibiting Shared and Generic Accounts
Account management policies often dictate that personnel should not use shared or generic accounts. Instead, each user has at least one account, which is only accessible to that user. If multiple users share a single account, you cannot implement basic authorization controls. As a reminder, four key concepts are:
• Identification. Users claim an identity with an identifier such as a username.
• Authentication. Users prove their identity using an authentication method such as a password.
• Authorization. Users are authorized access to resources, based on their proven identity.
• Accounting. Logs record activity using the users’ claimed identity.
Imagine that Bart, Maggie, and Lisa all used a Guest account. If you want to give Lisa access to certain files, you’d grant access to the Guest account, but Bart and Maggie would have the same access. If Bart deleted the files, logs would indicate the Guest account deleted the files, but you wouldn’t know who actually deleted them. In contrast, if users have unique user accounts, you can give them access to resources individually. Additionally, logs would indicate exactly who took an action.
Note that having a single, temporary user log on with the Guest account does support identification, authentication, authorization, and accounting. It is only when multiple users are sharing the same account that you lose these controls. Still, some organizations prohibit the use of the Guest account for any purposes.
Disablement Policies
Many organizations have a disablement policy that specifies how to manage accounts in different situations. For example, most organizations require administrators to disable user accounts as soon as possible when employees leave the organization. Additionally, it’s common to disable default accounts to prevent them from being used.
Disabling is preferred over deleting the account, at least initially. If administrators delete the account, they also delete any encryption and security keys associated with the account. However, these keys are retained when the account is disabled. As an example, imagine that an employee encrypted files with his account. The operating system uses cryptography keys to encrypt and decrypt these files. If administrators deleted this account, these files may remain encrypted forever unless the organization has a key escrow or recovery agent that can access the files.
Some contents of an account disablement policy include:
• Terminated employee. An account disablement policy specifies that accounts for ex-employees are disabled as soon as possible. This ensures a terminated employee doesn’t become a disgruntled ex-employee who wreaks havoc on the network. Note that “terminated” refers to both employees who resign and employees who are fired.
• Leave of absence. If an employee will be absent for an extended period, the account should be disabled while the employee is away. Organizations define extended period differently, with some organizations defining it as only two weeks, whereas other organizations extend it out to as long as two months.
• Delete account. When the organization determines the account is no longer needed, administrators delete it. For example, the policy may direct administrators to delete accounts that have been inactive for 60 or 90 days.
Recovering Accounts
In some situations, administrators need to recover accounts. The two primary account recovery scenarios are:
• Enable a disabled account. Administrators can reset the user’s password and take control of the account. Similarly, they pass control of the account to someone else, such as a supervisor or manager of an ex-employee. Administrators reset the user’s password, set it to expire on first use, and then give the password to the other person.
• Recover a deleted account. It is also possible to recover a deleted account. This is more complex than simply creating another account with the same name. Instead, administrators follow detailed procedures to recover the account.
Q. A recent security audit discovered several apparently dormant user accounts. Although users could log on to the accounts, no one had logged on to them for more than 60 days. You later discovered that these accounts are for contractors who work approximately one week every quarter. Which of the following is the BEST response to this situation?
A. Remove the account expiration from the accounts.
B. Delete the accounts.
C. Reset the accounts.
D. Disable the accounts.
Answer is D. The best response is to disable the accounts and then enable them when needed by the contractors.
Ideally, the accounts would include an expiration date so that they would automatically expire when no longer needed, but the scenario doesn’t indicate the accounts have an expiration date.
Because the contractors need to access the accounts periodically, it’s better to disable them rather than delete them.
Reset the accounts implies you are changing the password, but this isn’t needed.
See Chapter 2 of the CompTIA Security+: Get Certified Get Ahead: SY0-501 Study Guide for more information on managing accounts.