v0.1.0-draft AI Drafted
Home / Guides / Splunk

Splunk Hardening Guide

SIEM Last updated: 2025-12-14

SIEM platform hardening for role-based access, HEC tokens, and search controls

Overview

Splunk is the core SOC platform with 800+ Splunkbase integrations aggregating security logs from entire enterprises. API key compromise enables access to detection rules, threat intelligence, and incident response data—providing attackers complete visibility into defensive capabilities. SOAR playbook manipulation can disable automated response.

Intended Audience

  • Security engineers managing SIEM platforms
  • SOC administrators configuring Splunk
  • GRC professionals assessing security monitoring
  • Third-party risk managers evaluating SIEM integrations

Table of Contents

  1. Authentication & Access Controls
  2. API & App Security
  3. Data Security
  4. Monitoring & Detection

1. Authentication & Access Controls

1.1 Enforce SAML SSO with MFA

Profile Level: L1 (Baseline) NIST 800-53: IA-2(1)

Description

Require SAML SSO with MFA for all Splunk access.

Rationale

Why This Matters:

  • Splunk contains all security telemetry
  • Compromised access reveals defensive capabilities
  • Detection rules and playbooks are high-value intel

Attack Scenario: Compromised API credentials export detection rules; SOAR playbook manipulation disables automated response.

ClickOps Implementation

Step 1: Configure SAML SSO

  1. Navigate to: Settings → Access controls → Authentication method
  2. Select: SAML
  3. Configure IdP settings

Step 2: Map Roles

  1. Configure SAML attribute mapping
  2. Map IdP groups to Splunk roles

1.2 Implement Role-Based Access

Profile Level: L1 (Baseline) NIST 800-53: AC-3, AC-6

ClickOps Implementation

Step 1: Define Roles

Role Permissions
admin Full access (2-3 users)
sc_admin Splunk Cloud specific
power Search all data, create knowledge objects
user Search assigned indexes only
analyst SOC functions, no admin

Step 2: Configure Index Access

  1. Navigate to: Settings → Access controls → Roles
  2. For each role, configure:
    • Allowed indexes
    • Search restrictions
    • App access

2. API & App Security

2.1 Secure API Tokens

Profile Level: L1 (Baseline) NIST 800-53: IA-5

Description

Manage Splunk API tokens securely.

ClickOps Implementation

Step 1: Audit Existing Tokens

# List authentication tokens
curl -k -u admin:password \
  https://splunk:8089/services/authentication/tokens

Step 2: Create Scoped Tokens

  1. Create tokens with minimum permissions
  2. Set expiration (90 days max)
  3. Bind to specific IP addresses

2.2 Splunkbase App Security

Profile Level: L1 (Baseline) NIST 800-53: CM-7

ClickOps Implementation

Step 1: Review Installed Apps

  1. Navigate to: Apps → Manage Apps
  2. Review all installed apps
  3. Remove unused apps

Step 2: Configure App Installation Policy

  1. Restrict app installation to admins
  2. Require security review for new apps
  3. Update apps regularly

3. Data Security

3.1 Configure Index Access Controls

Profile Level: L1 (Baseline) NIST 800-53: AC-3

ClickOps Implementation

Step 1: Segment Indexes

Index Strategy:
├── security (SOC access only)
├── network (network team + SOC)
├── application (app teams)
└── audit (compliance + security)

Step 2: Configure Role-Index Mapping

  1. Navigate to: Settings → Access controls → Roles
  2. Configure: Indexes searched by default
  3. Restrict sensitive indexes

4. Monitoring & Detection

4.1 Monitor Splunk Itself

Profile Level: L1 (Baseline) NIST 800-53: AU-6

Detection Queries

# Detect unusual search activity
index=_audit action=search

| stats count by user, search
| where count > 100

# Detect configuration changes
index=_audit action=edit_*

| table _time user action object

# Detect failed authentication
index=_audit action=login status=failure

| stats count by user, src
| where count > 5

Appendix A: Edition Compatibility

Control Enterprise Cloud
SAML SSO ✅ ✅
Role-Based Access ✅ ✅
API Tokens ✅ ✅
Audit Logging ✅ ✅

Changelog

Date Version Maturity Changes Author
2025-12-14 0.1.0 draft Initial Splunk hardening guide Claude Code (Opus 4.5)