Access Control Lists (ACLs) in ServiceNow are security rules that control user access to data and functionality within the platform. They serve as gatekeepers, determining who can read, write, create, or delete records in tables and fields.<br><br>ACLs operate on a hierarchical evaluation system. W…Access Control Lists (ACLs) in ServiceNow are security rules that control user access to data and functionality within the platform. They serve as gatekeepers, determining who can read, write, create, or delete records in tables and fields.<br><br>ACLs operate on a hierarchical evaluation system. When a user attempts to access data, ServiceNow checks applicable ACL rules from most specific to least specific. The system evaluates table-level rules first, then field-level rules. If no ACL exists for a specific object, access is denied by default, following the principle of least privilege.<br><br>Each ACL rule consists of several key components. The Operation defines what action is being controlled, such as read, write, create, or delete. The Name specifies the table and optionally the field being protected. The Requires role field indicates which roles users must possess to pass the rule. Additionally, conditions can be set using scripts or simple filters to create more granular access control.<br><br>ACLs support three evaluation methods. Role-based checks verify if users have required roles assigned. Conditional checks use record-based conditions to filter access. Script-based checks allow complex logic through server-side JavaScript for sophisticated scenarios.<br><br>The evaluation order follows a specific pattern. ServiceNow first checks if any ACL applies to the request. Then it evaluates whether the user meets the role requirements. Next, it processes any conditions defined. Finally, it executes any scripts attached to the rule.<br><br>Best practices for ACL management include documenting all custom rules thoroughly, testing changes in sub-production environments before deployment, using roles rather than individual users for maintainability, and regularly auditing existing rules to ensure they align with current security requirements.<br><br>Understanding ACLs is essential for system administrators as they form the foundation of ServiceNows security model, protecting sensitive data while enabling appropriate access for users to perform their job functions effectively.
Access Control Lists (ACLs) in ServiceNow
Why Access Control Lists Are Important
Access Control Lists (ACLs) are fundamental to ServiceNow security. They determine who can access what data and what operations users can perform on that data. Without proper ACL configuration, sensitive information could be exposed to unauthorized users, or critical business processes could be disrupted by users making changes they shouldn't be able to make. ACLs protect organizational data integrity and ensure compliance with security policies.
What Are Access Control Lists?
ACLs are security rules that define permissions for accessing and manipulating data in ServiceNow. They control four main operations:
• Read - View records and fields • Write - Modify existing records and fields • Create - Add new records • Delete - Remove records
ACLs can be applied at the table level, field level, or even for specific operations like reporting or web services.
How ACLs Work
ACLs are evaluated based on a hierarchy of rules. When a user attempts to access data, ServiceNow checks applicable ACLs in a specific order:
1. Table-level ACLs are evaluated first 2. Field-level ACLs are evaluated next if the table-level check passes
Each ACL rule contains three key components:
• Requires Role - Specifies which roles grant access • Condition - A filter condition that must be true • Script - Advanced logic using server-side JavaScript
For access to be granted, at least one of these components must evaluate to true. If all three are empty, the ACL grants universal access.
ACL Processing Order
ServiceNow processes ACLs from most specific to least specific. A field-level ACL on a specific table takes precedence over a wildcard ACL. The system uses the format: table.field or uses asterisks (*) as wildcards.
The Admin Override
By default, users with the admin role bypass ACL checks. However, this behavior can be modified using the security_admin role for high-security contexts.
Debug ACLs
ServiceNow provides debugging tools to troubleshoot ACL issues. The Session Debug feature allows administrators to see which ACLs are being evaluated and their results.
Exam Tips: Answering Questions on Access Control Lists (ACLs)
1. Remember the hierarchy: Table-level ACLs must pass before field-level ACLs are even evaluated. Questions often test this concept.
2. Know the four operations: Read, Write, Create, and Delete. Exam questions frequently ask which operation type controls specific user actions.
3. Understand the OR logic: Within a single ACL rule, the three components (Requires Role, Condition, Script) use OR logic. A user needs to satisfy only one component to pass that ACL.
4. Wildcards matter: The asterisk (*) represents all tables or all fields. Know that *.* means all fields on all tables.
5. Admin role behavior: Remember that admin users typically bypass ACLs. Questions may ask about exceptions or how to enforce ACLs even for admins.
6. Field-level vs Table-level: If a question describes a scenario where a user can see a record but not a specific field, think about field-level ACLs being more restrictive.
7. Common scenarios: Be prepared for questions about restricting access based on user department, assignment group, or record state.
8. ACL debugging: Know that session debugging and security debugging tools exist to troubleshoot access issues.
9. Order of evaluation: More specific ACLs take priority. A rule for incident.short_description takes precedence over incident.* which takes precedence over *.*