Access Control Rules (ACLs) in ServiceNow are security mechanisms that control what data users can access and what operations they can perform on that data. They serve as gatekeepers protecting tables, fields, and records within the platform.
ACLs operate on three main levels: Table level (control…Access Control Rules (ACLs) in ServiceNow are security mechanisms that control what data users can access and what operations they can perform on that data. They serve as gatekeepers protecting tables, fields, and records within the platform.
ACLs operate on three main levels: Table level (controlling access to entire tables), Field level (restricting access to specific columns), and Record level (determining which rows users can view or modify). Each rule evaluates conditions to grant or deny permissions for read, write, create, and delete operations.
The structure of an ACL consists of several components. First, the Object being protected, which could be a table, field, or record. Second, the Operation type such as read, write, create, or delete. Third, the Conditions that must be met, which can include role requirements, scripts, or field conditions.
ServiceNow evaluates ACLs using a specific order of precedence. More specific rules take priority over general ones. For example, a field-level ACL takes precedence over a table-level ACL. When multiple rules apply, all conditions must pass for access to be granted.
Roles play a crucial part in ACL configuration. Administrators can require users to have specific roles before accessing protected resources. The admin role typically bypasses most ACL restrictions, which is why it should be assigned carefully.
Best practices for ACL management include testing rules thoroughly before deployment, using the Security Admin role to manage ACLs, documenting all custom rules, and following the principle of least privilege by granting minimum necessary access.
The ACL debugging tool helps administrators troubleshoot access issues by showing which rules are being evaluated and their results. This is essential for identifying why users might be experiencing permission problems.
Proper ACL configuration ensures data security, maintains compliance requirements, and provides users with appropriate access levels based on their organizational responsibilities within the ServiceNow platform.
Access Control Rules in ServiceNow - Complete Study Guide
Why Access Control Rules Are Important
Access Control Rules (ACLs) are fundamental to ServiceNow security. They determine who can read, write, create, or delete records and fields within the platform. Understanding ACLs is critical for the CSA exam because they protect sensitive data, ensure compliance with organizational policies, and maintain system integrity. A misconfigured ACL can expose confidential information or prevent users from completing their work.
What Are Access Control Rules?
Access Control Rules are security mechanisms that define permissions for tables, fields, and records in ServiceNow. They control four primary operations:
• Read - Ability to view records or field values • Write - Ability to modify existing records or field values • Create - Ability to insert new records • Delete - Ability to remove records
ACLs can be applied at three levels: 1. Table level - Controls access to entire tables 2. Field level - Controls access to specific fields within a table 3. Record level - Controls access based on specific conditions
How Access Control Rules Work
When a user attempts to access data, ServiceNow evaluates ACLs in a specific order:
1. The system checks if any ACL exists for the requested operation on that object 2. ACLs are evaluated from most specific to least specific (field-level before table-level) 3. All matching ACLs must pass for access to be granted 4. If no ACL exists, access is denied by default (for non-admin users)
Key Components of an ACL:
• Name - Identifies the table and field (format: table.field) • Operation - The type of access being controlled (read, write, create, delete) • Admin overrides - Whether admins bypass this rule • Active - Whether the rule is currently enforced • Condition - A filter that must be true for the ACL to apply • Script - Advanced logic using JavaScript • Requires role - Roles that grant access through this ACL
The ACL Evaluation Process
ServiceNow uses a matching rule system. When evaluating access:
1. Find all ACLs that match the object and operation 2. Evaluate each matching ACL 3. For each ACL, check: Does the user have a required role? Does the condition pass? Does the script return true? 4. If ANY one of these three requirements passes, that individual ACL passes 5. ALL matching ACLs must pass for access to be granted
Important Concepts for the Exam
• Wildcard ACLs - Using * applies rules to all tables or all fields • Inheritance - Child tables inherit ACLs from parent tables • Debug Security - A feature to troubleshoot ACL issues (found in System Security) • High Security Plugin - Adds additional security controls and stricter ACL enforcement
Exam Tips: Answering Questions on Access Control Rules
1. Remember the hierarchy - Field-level ACLs are evaluated before table-level ACLs. Both must pass if both exist.
2. Know the default behavior - If no ACL exists for a non-admin user, access is denied. Admins typically have full access unless 'Admin overrides' is unchecked.
3. Understand OR vs AND logic - Within a single ACL, roles, conditions, and scripts use OR logic (any one can grant access). Between multiple matching ACLs, AND logic applies (all must pass).
4. Watch for debugging questions - The Security Debug module helps identify why access is being denied or granted.
5. Table.None format - When you see table.None or table.*, understand this refers to table-level access rather than field-level.
6. Be cautious with 'all users' answers - ACLs that grant broad access are usually incorrect answers in security-focused questions.
7. Script execution - Remember that ACL scripts run on the server side and have access to the current object and answer variable.
8. Role requirement - Questions often test whether you understand that having a role listed in 'Requires role' is sufficient to pass that ACL, even with no condition or script.