CVE-2025-20228
📋 TL;DR
A Cross-Site Request Forgery (CSRF) vulnerability in Splunk Enterprise and Splunk Cloud Platform allows low-privileged users without admin or power roles to change the maintenance mode state of App Key Value Store (KVStore). This affects Splunk Enterprise versions below 9.3.3, 9.2.5, and 9.1.8, and Splunk Cloud Platform versions below 9.2.2403.108 and 9.1.2312.204.
💻 Affected Systems
- Splunk Enterprise
- Splunk Cloud Platform
📦 What is this software?
Splunk by Splunk
Splunk by Splunk
Splunk by Splunk
⚠️ Risk & Real-World Impact
Worst Case
An attacker could disrupt KVStore operations by enabling maintenance mode, potentially causing application functionality loss or data access issues for dependent apps.
Likely Case
Temporary disruption of specific applications relying on KVStore, requiring manual intervention to restore normal operations.
If Mitigated
Minimal impact with proper CSRF protections and role-based access controls in place.
🎯 Exploit Status
Exploitation requires an authenticated low-privileged user to be tricked into visiting a malicious website or clicking a crafted link.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Splunk Enterprise: 9.3.3, 9.2.5, 9.1.8; Splunk Cloud Platform: 9.2.2403.108, 9.1.2312.204
Vendor Advisory: https://advisory.splunk.com/advisories/SVD-2025-0303
Restart Required: Yes
Instructions:
1. Backup your Splunk configuration and data. 2. Download the appropriate patch from Splunk's official website. 3. Stop Splunk services. 4. Apply the patch following Splunk's upgrade documentation. 5. Restart Splunk services. 6. Verify the version is updated.
🔧 Temporary Workarounds
Implement CSRF Protection Headers
allAdd CSRF tokens or same-site cookie attributes to protect against cross-site request forgery attacks.
Configure web server or application firewall to add CSRF protection headers
Restrict Access to KVStore Maintenance Interface
allLimit network access to the KVStore maintenance endpoints to trusted users only.
Configure firewall rules or network ACLs to restrict access to Splunk web interface ports
🧯 If You Can't Patch
- Implement strict role-based access control and monitor for unauthorized KVStore maintenance mode changes.
- Use web application firewalls with CSRF protection rules and educate users about phishing risks.
🔍 How to Verify
Check if Vulnerable:
Check Splunk version via web interface or command line. If version is below patched versions, system is vulnerable.Check Version:
On Splunk server: $SPLUNK_HOME/bin/splunk versionVerify Fix Applied:
Confirm Splunk version is at or above the patched versions listed in the fix section.📡 Detection & Monitoring
Log Indicators:
- Log entries showing KVStore maintenance mode changes by non-admin users
- Unexpected CSRF token validation failures
Network Indicators:
- HTTP POST requests to KVStore maintenance endpoints from unexpected sources
SIEM Query:
index=_internal source=*web_access.log (KVStore OR maintenance) AND (POST OR PUT) AND status=200