CVE-2025-20386
📋 TL;DR
This vulnerability allows non-administrator users on Windows systems to access the Splunk Enterprise installation directory and all its contents after a new installation or upgrade. This affects Splunk Enterprise for Windows installations below specific patched versions. The improper permissions assignment could lead to unauthorized access to sensitive configuration files and data.
💻 Affected Systems
- Splunk Enterprise for Windows
📦 What is this software?
Splunk by Splunk
Splunk by Splunk
Splunk by Splunk
Splunk by Splunk
⚠️ Risk & Real-World Impact
Worst Case
Non-administrator users could access and modify Splunk configuration files, credentials, or sensitive data, potentially leading to privilege escalation, data exfiltration, or service disruption.
Likely Case
Unauthorized users reading sensitive configuration files containing credentials, encryption keys, or system information that could be used for further attacks.
If Mitigated
Limited impact if proper access controls and monitoring are in place, though the vulnerability still presents an unnecessary risk surface.
🎯 Exploit Status
Exploitation requires local user access to the Windows system. The vulnerability is straightforward to exploit once an attacker has local access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Upgrade to Splunk Enterprise 10.0.2, 9.4.6, 9.3.8, or 9.2.10 or later
Vendor Advisory: https://advisory.splunk.com/advisories/SVD-2025-1205
Restart Required: Yes
Instructions:
1. Download the patched version from Splunk's official website. 2. Backup your Splunk configuration and data. 3. Run the installer to upgrade to a patched version. 4. Restart Splunk services after installation.
🔧 Temporary Workarounds
Manual Permissions Correction
windowsManually set correct permissions on the Splunk installation directory to restrict access to administrators only.
icacls "C:\Program Files\Splunk" /inheritance:r /grant:r "Administrators:(OI)(CI)F" /grant:r "SYSTEM:(OI)(CI)F"
🧯 If You Can't Patch
- Apply the manual permissions correction workaround immediately
- Implement strict access controls and monitoring on Splunk servers, limiting local user access
🔍 How to Verify
Check if Vulnerable:
Check Splunk version via web interface (Settings > Server Info) or command line, and verify if installation directory permissions allow non-administrator access.Check Version:
splunk versionVerify Fix Applied:
Verify Splunk version is patched and check that only administrators have access to the installation directory using Windows permissions tools.📡 Detection & Monitoring
Log Indicators:
- Unauthorized access attempts to Splunk installation directory in Windows security logs
- Splunk service failures or unexpected restarts
Network Indicators:
- Unusual outbound connections from Splunk servers
SIEM Query:
source="WinEventLog:Security" EventCode=4663 ObjectName="*Program Files\\Splunk*" AND NOT SubjectUserName="*SYSTEM" AND NOT SubjectUserName="*Administrator*"