Published: 2025-12-03
Overview
CVE-2025-20387 is a high-severity vulnerability affecting Splunk Universal Forwarder for Windows versions below 10.0.2, 9.4.6, 9.3.8, and 9.2.10. This vulnerability arises from incorrect permissions being assigned to the Universal Forwarder installation directory during a new installation or upgrade process. This flaw allows non-administrator users on the affected machine to gain unauthorized access to the installation directory and its contents.
Technical Details
The root cause of CVE-2025-20387 lies in the installation or upgrade scripts of affected Splunk Universal Forwarder versions. These scripts incorrectly set the permissions on the installation directory, granting broader access than intended. This misconfiguration enables standard user accounts to read, write, and potentially execute files within the directory, which could lead to various security compromises.
CVSS Analysis
This vulnerability has been assigned a CVSS score of 8.0 (HIGH). This high score reflects the significant potential impact of the vulnerability, including:
- Unauthorized Data Access: Non-privileged users can access sensitive configuration files, logs, and other data within the Universal Forwarder installation directory.
- Potential for Lateral Movement: Malicious actors could exploit this vulnerability to gain a foothold on the system and potentially move laterally within the network.
- Compromise of Universal Forwarder Functionality: Users with unauthorized access could modify configuration files, potentially disrupting or compromising the Universal Forwarder’s ability to collect and forward data.
Possible Impact
The exploitation of CVE-2025-20387 can have severe consequences, including:
- Data Breach: Sensitive data collected by the Universal Forwarder could be exposed to unauthorized users.
- System Compromise: Malicious actors could leverage the vulnerability to gain control of the affected system.
- Compliance Violations: Organizations could face compliance violations due to the unauthorized access and potential data breach.
Mitigation and Patch Steps
To address CVE-2025-20387, it is strongly recommended to upgrade to one of the following Splunk Universal Forwarder for Windows versions:
- 10.0.2 or later
- 9.4.6 or later
- 9.3.8 or later
- 9.2.10 or later
Follow these steps to mitigate the vulnerability:
- Download the latest version: Download the appropriate updated version of Splunk Universal Forwarder from the Splunk website.
- Backup Configuration: Before upgrading, back up your existing Splunk Universal Forwarder configuration files.
- Upgrade: Follow the official Splunk upgrade documentation to install the updated version.
- Verify Permissions: After the upgrade, verify that the permissions on the Universal Forwarder installation directory are correctly set, ensuring that only authorized users have access.
If immediate upgrade is not possible, temporarily restrict the permissions on the Universal Forwarder installation directory to only allow access to administrator accounts. Note that this may impact the functionality of the Universal Forwarder and should only be considered a short-term workaround.
