CVE-2024-36989
📋 TL;DR
This CVE allows low-privileged users without admin or power roles to create notifications in Splunk Web Bulletin Messages that are broadcast to all users on the instance. It affects Splunk Enterprise versions below 9.2.2, 9.1.5, and 9.0.10, and Splunk Cloud Platform versions below 9.1.2312.200. This improper access control vulnerability could enable unauthorized message dissemination across the organization.
💻 Affected Systems
- Splunk Enterprise
- Splunk Cloud Platform
📦 What is this software?
Cloud by Splunk
Splunk by Splunk
Splunk by Splunk
Splunk by Splunk
⚠️ Risk & Real-World Impact
Worst Case
An attacker with low-privileged access could broadcast malicious or misleading notifications to all Splunk users, potentially causing operational disruption, spreading misinformation, or facilitating social engineering attacks against administrators.
Likely Case
Low-privileged users could broadcast unauthorized messages to all users, creating confusion, spreading inappropriate content, or disrupting normal operations through spam notifications.
If Mitigated
With proper role-based access controls and monitoring, impact is limited to minor notification spam that can be quickly identified and removed by administrators.
🎯 Exploit Status
Exploitation requires authenticated low-privileged access. The vulnerability is straightforward to exploit once an attacker has valid credentials.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Splunk Enterprise: 9.2.2, 9.1.5, 9.0.10; Splunk Cloud Platform: 9.1.2312.200
Vendor Advisory: https://advisory.splunk.com/advisories/SVD-2024-0709
Restart Required: Yes
Instructions:
1. Backup your Splunk configuration and data. 2. Download the appropriate patch version from Splunk's website. 3. Stop all Splunk services. 4. Apply the patch following Splunk's upgrade documentation. 5. Restart Splunk services. 6. Verify the version is updated.
🔧 Temporary Workarounds
Restrict Bulletin Message Creation
allTemporarily restrict all users from creating bulletin messages until patching is complete.
# Review and modify role capabilities in Splunk Web or via CLI
# Remove 'edit_bulletin_messages' capability from non-admin roles
Monitor Bulletin Message Activity
allImplement enhanced monitoring of bulletin message creation and review all existing messages.
# Search for bulletin message creation: index=_audit action="edit_bulletin_messages"
# Review current messages: Navigate to Settings > Server settings > Bulletin messages in Splunk Web
🧯 If You Can't Patch
- Implement strict role-based access controls to limit which users can create bulletin messages.
- Enable detailed auditing of bulletin message activities and set up alerts for unauthorized creation attempts.
🔍 How to Verify
Check if Vulnerable:
Check your Splunk version via the web interface (Settings > Server settings > Server info) or CLI command. Compare against affected versions.Check Version:
On Splunk server: /opt/splunk/bin/splunk versionVerify Fix Applied:
After patching, verify the version is at or above the fixed versions. Test with a low-privileged user account that creating bulletin messages is properly restricted.📡 Detection & Monitoring
Log Indicators:
- Audit logs showing bulletin message creation by non-admin users
- Unexpected bulletin messages in the system
Network Indicators:
- Unusual API calls to bulletin message endpoints from low-privileged accounts
SIEM Query:
index=_audit action="edit_bulletin_messages" user!=admin* | stats count by user, _time