Password and Credential Management for BAS

Poor credential management is a leading cause of BAS security incidents. This guide covers best practices for passwords, accounts, and secrets management.

The Problem

Common Credential Issues

Issue	Risk
Default passwords	Easy compromise
Shared accounts	No accountability
Weak passwords	Brute force attacks
Passwords in documentation	Unauthorized access
No password rotation	Long-term compromise
Same password everywhere	Single breach = full access

Real-World Impact

ICS-CERT and CISA advisories frequently cite:

• Default credentials left unchanged
• Hard-coded passwords in firmware
• Weak authentication mechanisms
• Lack of audit trails

Password Requirements

Minimum Standards

Attribute	Requirement
Length	12+ characters (16+ for admin)
Complexity	Upper, lower, number, special
Uniqueness	Different for each system
History	Cannot reuse last 12 passwords
Maximum age	90 days (or longer with MFA)
Lockout	After 5 failed attempts

Password Strength Examples

Strength	Example	Time to Crack
Weak	password123	Seconds
Medium	P@ssw0rd!	Hours
Strong	Tr0ub4dor&3#Horse	Years
Very Strong	Random 16+ chars	Centuries

Account Management

Account Types

Type	Purpose	Management
Service accounts	System-to-system	Long passwords, no interactive
Admin accounts	Configuration	Strong auth, limited use
Operator accounts	Daily use	Standard policy
Vendor accounts	Support access	Time-limited, audited

Principle of Least Privilege

Each account should have only required access:

Engineer Account:
   ✓ Read/write configuration
   ✓ Acknowledge alarms
   ✗ User management
   ✗ Security settings

Operator Account:
   ✓ View graphics
   ✓ Acknowledge alarms
   ✓ Adjust setpoints (limited range)
   ✗ Configuration changes
   ✗ Programming

Eliminating Shared Accounts

Instead Of	Use
"admin" shared by all	Individual admin accounts
"operator" for day shift	User-specific accounts
"contractor" for all vendors	Per-company, time-limited

Default Credential Remediation

Discovery Process

1. Inventory all devices with web interfaces or logins
2. Document default credentials from manuals
3. Test for defaults (authorized testing only)
4. Prioritize by risk (internet-facing first)

Common BAS Default Credentials

Note: Change these immediately upon deployment.

Platform	Common Defaults
Niagara	admin/admin, tridium/tridium
Metasys	MetasysSysAgent/[varies]
Many others	admin/admin, admin/password

Remediation Steps

1. Change all default passwords
2. Rename or disable default accounts where possible
3. Create role-based accounts
4. Document in secure location (not in drawings)
5. Verify changes were applied

Password Storage

Where NOT to Store Passwords

Location	Risk
Sticky notes	Physical access = compromise
Shared spreadsheets	Too many people can access
Email	Easily forwarded/leaked
Drawing submittals	Distributed widely
Unencrypted files	Easy to copy/steal

Recommended Storage

Method	Appropriate For
Password manager	Individual use
Enterprise vault	Shared/service accounts
Hardware security module	Critical secrets

Password Manager Features

• Encrypted storage
• Access logging
• Role-based sharing
• Password generation
• Expiration tracking

Service Account Management

Best Practices

Practice	Implementation
Long passwords	25+ random characters
No interactive login	Service only
Minimum permissions	Only required access
Regular rotation	Annual minimum
Documented purpose	Why account exists

API Keys and Tokens

Guideline	Reason
Never embed in code	Code is often shared/leaked
Use environment variables	Easier to rotate
Implement expiration	Limit exposure window
Scope appropriately	Minimum required permissions
Audit usage	Detect misuse

Multi-Factor Authentication

When to Require MFA

Access Type	MFA Required?
Remote access	Yes
Admin accounts	Yes
Local workstation	Recommended
Service accounts	Not applicable
Public-facing	Yes

MFA Options

Method	Security Level
SMS code	Low (SIM swapping risk)
Authenticator app	Medium
Hardware token	High
Biometric	Medium-High
Smart card	High

Vendor and Contractor Access

Temporary Access Process

1. Request submitted with justification
2. Approval from system owner
3. Time-limited account created
4. Access logged throughout
5. Account disabled at end of work
6. Activity reviewed

Vendor Account Requirements

Requirement	Purpose
Individual accounts	Accountability
Expiration date	Automatic termination
Limited scope	Only needed access
Session logging	Audit trail
Notification on creation/use	Awareness

Audit and Monitoring

What to Log

Event	Purpose
Login success	Usage tracking
Login failure	Attack detection
Password changes	Change management
Account creation	Access control
Privilege escalation	Security monitoring

Review Frequency

Review	Frequency
Failed login attempts	Daily
Active accounts	Monthly
Admin account usage	Weekly
Service account inventory	Quarterly
Password age report	Monthly

Incident Response

If Credentials Compromised

Immediate:
1. Change affected passwords
2. Disable compromised accounts
3. Review access logs
4. Check for unauthorized changes

Short-term:
5. Assess scope of compromise
6. Notify stakeholders
7. Implement additional controls
8. Document incident

Long-term:
9. Root cause analysis
10. Improve processes
11. Additional training

References

• CISA ICS-CERT Advisories - Vulnerability alerts
• NIST SP 800-63B - Digital Identity Guidelines
• CIS Controls - Security benchmarks
• Manufacturer security guides - Product-specific guidance