6.3 Exclusive Access, One-Time Passwords (OTP) & Check-out Automation

6.3 Exclusive Access, One-Time Passwords (OTP) & Check-out Automation

Quick Answer: Exclusive Access enforces the Check-out / Check-in paradigm in CyberArk PAS, locking a privileged account to a single active user and preventing concurrent session collisions or shared attribution ambiguity. When paired with One-Time Passwords (OTP), checking in the account—or the expiration of the configured MinValidityPeriod—automatically triggers the Central Policy Manager (CPM) to execute an immediate password change on the target endpoint. This zero-standing-privilege architecture ensures that credentials exposed to administrators or third-party vendors become invalid immediately after use, neutralizing credential harvesting and post-session abuse.

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The Concurrency Dilemma & Exclusive Access Architecture

Sharing privileged accounts (Administrator, root, sa) introduces severe operational and security vulnerabilities:

• Session Collisions: Multiple administrators concurrently logged in under the same identity can overwrite configurations, disrupt services, or kill active processes.
• Attribution Ambiguity: Host audit logs cannot attribute actions to a specific individual under a shared identity, eliminating non-repudiation.

CyberArk resolves this through Exclusive Access (the Check-out / Check-in workflow). Governed by the Master Policy rule "Enforce check-in/check-out exclusive access", the Vault enforces single-user locking:

1. Check-Out: Viewing, copying, or connecting via PSM locks the account, setting LockedBy = UserID with a lock timestamp.
2. Lockout Enforcement: Other users attempting access are blocked with an explicit message indicating the account is locked.
3. Check-In: Clicking Check In in PVWA releases the lock, restoring the account to an available state for other authorized users.

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The MinValidityPeriod & Check-Out Timeframe Configuration

The MinValidityPeriod parameter (configured in platform policy under Automatic Password Management) defines the minimum duration (in minutes) an account remains exclusively locked to the requester:

• Change Prevention: If a periodic CPM password change is due while an account is checked out, CPM delays rotation until release, preventing mid-session lockouts during active maintenance.
• Automatic Check-In (Auto-Release): If an administrator forgets to manually check in the account, the Vault automatically releases the lock once MinValidityPeriod expires.
• Timeframe Extensions: Administrators can extend active check-out timeframes in PVWA within platform maximum validity thresholds.

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One-Time Password (OTP) Behavior & Check-In Automation

Standard check-in leaves the target password unchanged. If an administrator recorded the password or their workstation harbored keyloggers, the credential remains vulnerable.

One-Time Password (OTP)—governed by the Master Policy rule "Enforce one-time password access" (requiring Exclusive Access)—transforms static privileged accounts into single-use ephemeral credentials:

1. Check-Out: The user retrieves the plaintext credential or injects it into a PSM connection.
2. Execution: The user performs administrative tasks on the target endpoint.
3. Release Trigger: The user clicks Check In, the PSM session terminates, or MinValidityPeriod elapses.
4. Immediate Task Generation: The Vault registers check-in and flags the account for an immediate CPM password change (ChangeTask).
5. Target Rotation: On its next polling loop over TCP port 1858, the CPM contacts the target (via SMB/RPC, SSH, SQL, or REST API), generates a new cryptographically random password, updates the target endpoint, updates the Vault Safe, and clears the change task.

Once rotated, the previously exposed password becomes completely invalid on the target, neutralizing credential harvesting.

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Just-In-Time (JIT) Access Concepts & Ephemeral Privilege

Exclusive Access and OTP establish the foundation for Just-In-Time (JIT) Access, replacing standing privileges with dynamic, short-lived rights:

• Ephemeral Active Directory Group Membership: CyberArk adds the user's personal account to privileged AD groups (Domain Admins) upon ticket approval with a time-to-live (TTL) countdown, automatically removing them upon expiration.
• Ephemeral Local Administrator Accounts: CyberArk dynamically provisions temporary local administrator accounts on target endpoints, injects random credentials, and deletes or disables the accounts upon session completion.
• Zero Standing Privilege (ZSP): Eliminating permanent administrative passwords across enterprise endpoints neutralizes Pass-the-Hash, Kerberoasting, and local SAM dumping attacks.

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Triad Comparison: Exclusive Access, OTP & Dual Control

Dual Control, Exclusive Access, and OTP represent three complementary security controls operating across distinct lifecycle phases:

• Dual Control = Pre-Access Authorization: Enforces Four-Eyes approval and ticketing validation before access is granted.
• Exclusive Access = Concurrency Control: Guarantees single-user locking, preventing session collisions and ensuring audit attribution.
• One-Time Password (OTP) = Post-Access Hygiene: Automatically rotates credentials upon check-in, neutralizing credential theft.

The following table summarizes their differences and operational interactions:

When combined on critical Tier-0 assets, this triad establishes the Gold Standard PAM Workflow: a requester must obtain manager approval via Dual Control, receives exclusive single-user lock via Exclusive Access, operates through an isolated PSM session, and upon session termination, the CPM immediately rotates the password via OTP.