Least Privilege and Privileged Access Management

Most intrusions start with an ordinary account: a phished user, a guessed password, a compromised laptop. What turns that foothold into a serious incident is privilege. With administrator rights, an attacker can disable security tools, reach every system, steal data at scale and deploy ransomware across the network.

Least privilege is the principle that every user, administrator, application and service should have only the access it needs to do its job. It appears in NIST SP 800-53, NIST SP 800-171 and CMMC, and it is one of the most effective ways to limit the damage from any single compromised account.

Separate admin accounts

Administrators should not use the same account for daily work and for administration. A privileged account that is also used to read email and browse the web is exposed to every phishing message and malicious site its owner encounters.

• Give each administrator a separate privileged account used only for administrative tasks.
• Never use privileged accounts for email or web browsing.
• Use dedicated, hardened workstations for the most sensitive administration, such as identity systems and security tools.
• Separate administration by tier, so accounts that manage domain controllers are not used on ordinary servers and workstations where their credentials could be captured.
• Remove local administrator rights from everyday user accounts.

Just-in-time access

Standing privilege, where accounts hold administrator rights at all times, means a stolen credential is immediately useful. Just-in-time access grants elevated rights only when needed, for a limited time and often with approval, then removes them automatically.

An administrator who needs to change a firewall rule requests access, receives it for an hour, makes the change and loses it again. If that account is compromised outside that window, the attacker gains an ordinary account. Many cloud platforms and identity providers include just-in-time features that are worth turning on.

Privileged access management

Privileged access management (PAM) tools bring control and visibility to the most powerful accounts:

• Credential vaulting stores privileged passwords and keys securely, often rotating them after each use so administrators never know them.
• Session brokering lets administrators connect to systems through the PAM tool without handling the credentials directly.
• Session recording captures what was done with privileged access, which supports investigations and accountability.
• Approval workflows require a second person to approve access to the most sensitive systems.

PAM is a significant project. Start with the highest-value accounts, such as domain administrators, cloud tenant administrators and backup administrators, and expand from there.

Do not forget service accounts

Service accounts let applications and scheduled tasks authenticate to other systems. They are often over-privileged, have passwords that never change, and are excluded from MFA. Attackers look for them because they provide quiet, persistent access.

• Inventory every service account and record its owner and purpose.
• Grant only the permissions each application needs, and avoid domain administrator rights.
• Use managed service accounts or workload identities where the platform supports them, so credentials rotate automatically.
• Restrict where service accounts can log in and alert on interactive logons.
• Remove secrets from scripts and source code and store them in a vault.

Access reviews

Permissions accumulate. People change roles and keep old access, projects end but their groups remain, and temporary exceptions become permanent. Regular access reviews catch this drift. Have system and data owners, not just IT, confirm who should have access, review privileged groups more often than standard ones, and remove access promptly when people leave or change roles.

Monitor privileged activity

Even with good controls, watch for misuse. Alert on additions to privileged groups, logons by privileged accounts at unusual times or from unusual systems, and attempts to disable logging or security tools. These are among the most valuable detections a security team can have. Our cyber hunt team regularly looks for signs of privilege abuse in client environments.

How CDT can help

CDT helps organizations design and implement least privilege. Our hardening engineers restructure administrative access and service accounts, and our penetration testing team shows how far an attacker could get from a single compromised user account.