---
name: performing-service-account-credential-rotation
description: Automates credential rotation for service accounts across Active Directory,
  cloud platforms, and application databases to eliminate stale secrets and reduce
  compromise risk. Use when rotating or automating rotation of service account passwords,
  API keys, or secrets stored in a vault.
domain: cybersecurity
subdomain: identity-access-management
tags:
- service-accounts
- credential-rotation
- secrets-management
- pam
- automation
- vault
version: '1.0'
author: mahipal
license: Apache-2.0
nist_csf:
- PR.AA-01
- PR.AA-02
- PR.AA-05
- PR.AA-06
mitre_attack:
- T1078
- T1110
- T1556
- T1098
- T1003
mitre_f3:
  version: '1.1'
  tactics:
  - initial-access
  - positioning
  - stealth
  techniques:
  - id: F1006.001
    name: 'Account Takeover: Exposed API Key'
    tactic: initial-access
    source: f3
  - id: F1006.002
    name: 'Account Takeover: Exposed Login Credential'
    tactic: initial-access
    source: f3
  - id: T1110
    name: Brute Force
    tactic: initial-access
    source: attack
  - id: F1005
    name: Account Manipulation
    tactic: positioning
    source: f3
  - id: F1023
    name: Device Fingerprint Spoofing
    tactic: stealth
    source: f3
---

# Performing Service Account Credential Rotation

## Overview

Service accounts are non-human identities used by applications, daemons, CI/CD pipelines, and automated processes to authenticate to systems and APIs. These accounts often have elevated privileges and their credentials (passwords, API keys, certificates, tokens) are frequently long-lived and shared across teams, making them prime targets for attackers. Credential rotation is the systematic process of replacing these secrets on a scheduled basis, propagating new credentials to all dependent systems, and verifying service continuity after rotation.


## When to Use

- When conducting security assessments that involve performing service account credential rotation
- When following incident response procedures for related security events
- When performing scheduled security testing or auditing activities
- When validating security controls through hands-on testing

## Prerequisites

- Inventory of all service accounts across AD, cloud, and applications
- Secrets management platform (HashiCorp Vault, AWS Secrets Manager, Azure Key Vault, or CyberArk)
- Service dependency mapping (which services use which credentials)
- Change management process for rotation windows
- Monitoring for service health post-rotation

## Core Concepts

### Service Account Types

| Type | Platform | Credential | Rotation Method |
|------|----------|-----------|-----------------|
| Active Directory Service Account | Windows/AD | Password | gMSA (automatic) or PAM-managed |
| AWS IAM User | AWS | Access Key/Secret Key | AWS Secrets Manager rotation Lambda |
| GCP Service Account | GCP | JSON key file | Key rotation via IAM API |
| Azure Service Principal | Azure | Client secret/certificate | Key Vault + rotation policy |
| Database Service Account | SQL/Oracle/Postgres | Password | Vault dynamic secrets |
| API Key | SaaS applications | API token | Application-specific API |

### Group Managed Service Accounts (gMSA)

Windows gMSAs provide automatic password management by Active Directory:
- AD automatically rotates the password every 30 days
- Password is 240 bytes, cryptographically random
- Multiple servers can use the same gMSA simultaneously
- No administrator knows or manages the password
- Eliminates manual rotation for Windows services

### Rotation Architecture

```
Secrets Manager / Vault
        │
        ├── Rotation Trigger (schedule or on-demand)
        │
        ├── Generate new credential
        │
        ├── Update credential at source (AD, cloud IAM, database)
        │
        ├── Update credential in all consumers:
        │   ├── Application configuration
        │   ├── CI/CD pipeline secrets
        │   ├── Kubernetes secrets
        │   └── Other dependent services
        │
        ├── Verify service health
        │   ├── Health check endpoints
        │   ├── Authentication test
        │   └── Functional smoke test
        │
        └── Revoke old credential (after grace period)
```

## Workflow

### Step 1: Discover and Inventory Service Accounts

Enumerate all service accounts and their dependencies:

```powershell
# Active Directory: Find all service accounts
Get-ADServiceAccount -Filter * -Properties *
Get-ADUser -Filter {ServicePrincipalName -ne "$null"} -Properties ServicePrincipalName,PasswordLastSet,LastLogonDate

# Find accounts with passwords older than 90 days
$threshold = (Get-Date).AddDays(-90)
Get-ADUser -Filter {PasswordLastSet -lt $threshold -and Enabled -eq $true} -Properties PasswordLastSet,ServicePrincipalName |
    Where-Object {$_.ServicePrincipalName} |
    Select-Object Name, PasswordLastSet, ServicePrincipalName
```

### Step 2: Implement gMSA for Windows Services

```powershell
# Create KDS Root Key (one-time, domain-wide)
Add-KdsRootKey -EffectiveImmediately

# Create the gMSA account
New-ADServiceAccount -Name "svc-webapp-gmsa" `
    -DNSHostName "svc-webapp-gmsa.corp.example.com" `
    -PrincipalsAllowedToRetrieveManagedPassword "WebServerGroup" `
    -KerberosEncryptionType AES128,AES256

# Install on target server
Install-ADServiceAccount -Identity "svc-webapp-gmsa"

# Test the account
Test-ADServiceAccount -Identity "svc-webapp-gmsa"

# Configure IIS Application Pool to use gMSA
# Set identity to: CORP\svc-webapp-gmsa$
```

### Step 3: AWS Access Key Rotation with Secrets Manager

```python
import boto3
import json

def rotate_iam_access_key(secret_arn, iam_username):
    """Rotate an IAM user's access key via Secrets Manager."""
    iam = boto3.client("iam")
    sm = boto3.client("secretsmanager")

    # Create new access key
    new_key = iam.create_access_key(UserName=iam_username)
    new_access_key = new_key["AccessKey"]["AccessKeyId"]
    new_secret_key = new_key["AccessKey"]["SecretAccessKey"]

    # Store new credentials in Secrets Manager
    sm.put_secret_value(
        SecretId=secret_arn,
        SecretString=json.dumps({
            "accessKeyId": new_access_key,
            "secretAccessKey": new_secret_key,
            "username": iam_username,
        })
    )

    # List old access keys and deactivate them
    keys = iam.list_access_keys(UserName=iam_username)
    for key in keys["AccessKeyMetadata"]:
        if key["AccessKeyId"] != new_access_key and key["Status"] == "Active":
            iam.update_access_key(
                UserName=iam_username,
                AccessKeyId=key["AccessKeyId"],
                Status="Inactive"
            )

    return {"new_key_id": new_access_key, "old_keys_deactivated": True}
```

### Step 4: Database Credential Rotation with Vault

```python
import hvac

def configure_vault_database_rotation(vault_url, vault_token, db_config):
    """Configure HashiCorp Vault for automatic database credential rotation."""
    client = hvac.Client(url=vault_url, token=vault_token)

    # Enable database secrets engine
    client.sys.enable_secrets_engine(
        backend_type="database",
        path="database"
    )

    # Configure database connection
    client.secrets.database.configure(
        name=db_config["name"],
        plugin_name="postgresql-database-plugin",
        connection_url=f"postgresql://{{{{username}}}}:{{{{password}}}}@"
                       f"{db_config['host']}:{db_config['port']}/{db_config['database']}",
        allowed_roles=[db_config["role_name"]],
        username=db_config["admin_user"],
        password=db_config["admin_password"],
    )

    # Create a role for dynamic credentials
    client.secrets.database.create_role(
        name=db_config["role_name"],
        db_name=db_config["name"],
        creation_statements=[
            "CREATE ROLE \"{{name}}\" WITH LOGIN PASSWORD '{{password}}' VALID UNTIL '{{expiration}}';",
            f"GRANT SELECT, INSERT, UPDATE, DELETE ON ALL TABLES IN SCHEMA public TO \"{{{{name}}}}\";"
        ],
        default_ttl="1h",
        max_ttl="24h",
    )

    return {"status": "configured", "role": db_config["role_name"]}
```

### Step 5: Post-Rotation Verification

After every rotation, verify service continuity:

```python
import requests
import time

def verify_service_health(service_endpoints, max_retries=3, delay=10):
    """Check that services are healthy after credential rotation."""
    results = []
    for endpoint in service_endpoints:
        for attempt in range(max_retries):
            try:
                response = requests.get(
                    endpoint["health_url"],
                    timeout=10,
                    headers=endpoint.get("headers", {})
                )
                healthy = response.status_code == 200
                results.append({
                    "service": endpoint["name"],
                    "status": "healthy" if healthy else f"unhealthy ({response.status_code})",
                    "attempt": attempt + 1,
                })
                if healthy:
                    break
            except requests.RequestException as e:
                results.append({
                    "service": endpoint["name"],
                    "status": f"error: {str(e)}",
                    "attempt": attempt + 1,
                })
            if attempt < max_retries - 1:
                time.sleep(delay)

    return results
```

## Validation Checklist

- [ ] Complete inventory of service accounts with dependency mapping
- [ ] gMSA implemented for all eligible Windows service accounts
- [ ] Cloud access keys rotated via secrets manager (AWS, GCP, Azure)
- [ ] Database credentials managed via dynamic secrets (Vault) or rotation policy
- [ ] Rotation schedule defined (30-90 days depending on risk level)
- [ ] Post-rotation health checks automated
- [ ] Alerting configured for rotation failures
- [ ] Old credentials revoked after grace period
- [ ] Rotation events logged and auditable
- [ ] Rollback procedure documented and tested

## References

- [Google Cloud Service Account Key Rotation](https://cloud.google.com/iam/docs/key-rotation)
- [AWS Secrets Manager Rotation](https://docs.aws.amazon.com/secretsmanager/latest/userguide/rotating-secrets.html)
- [Microsoft gMSA Documentation](https://learn.microsoft.com/en-us/windows-server/security/group-managed-service-accounts/group-managed-service-accounts-overview)
- [HashiCorp Vault Database Secrets Engine](https://developer.hashicorp.com/vault/docs/secrets/databases)
