Critical Splunk Enterprise Vulnerabilities Expose Systems to Privilege Escalation
Recent disclosures have unveiled high-severity vulnerabilities in Splunk’s Enterprise and Universal Forwarder products for Windows, stemming from incorrect file permissions during installation and upgrades. These flaws, identified as CVE-2025-20386 for Splunk Enterprise and CVE-2025-20387 for Universal Forwarder, allow non-administrator users to access sensitive installation directories and their contents, creating a pathway for privilege escalation attacks.
Understanding the Vulnerabilities
The core issue arises during fresh installations or version upgrades of the affected Splunk products on Windows systems. The installation process incorrectly assigns permissions to the default installation directories—C:\Program Files\Splunk for Enterprise and C:\Program Files\SplunkUniversalForwarder for Universal Forwarder. This misconfiguration grants unprivileged local users read and write access to sensitive configuration files, executable binaries, and other critical components that should remain restricted to administrators.
Technical Details
– CVE IDs: CVE-2025-20386 (Enterprise), CVE-2025-20387 (Forwarder)
– CVSS Score: 8.0 (High)
– CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
– CWE: CWE-732 (Incorrect Permission Assignment)
An attacker with local access could exploit these permissions to modify system configurations, inject malicious code, or escalate their privileges to the administrator level. Splunk rates both vulnerabilities as CVSS 8.0 (High severity), reflecting the significant risk to affected environments. The attack vector is network-adjacent, requiring authenticated access and user interaction, but the impact extends across the confidentiality, integrity, and availability of affected systems.
Immediate Remediation Steps
To address these vulnerabilities, Splunk has released patched versions:
– Splunk Enterprise: 10.0.2, 9.4.6, 9.3.8, or 9.2.10
– Splunk Universal Forwarder: 10.0.2, 9.4.6, 9.3.8, or 9.2.10
Organizations are strongly advised to upgrade to these versions immediately to mitigate potential risks.
Mitigation Measures for Immediate Action
For organizations unable to upgrade immediately, Splunk provides mitigation steps using `icacls` commands to reconfigure directory permissions. These steps involve removing inappropriate access rights and reapplying proper inheritance controls to ensure that only authorized users have access to sensitive directories and files.
Broader Implications and Recommendations
Given Splunk Enterprise’s prominence in security operations across Fortune 500 companies and government agencies, the discovery of these vulnerabilities underscores the critical importance of maintaining strict access controls and regularly reviewing system permissions. Organizations should prioritize patching and, in the interim, apply the recommended mitigation measures to protect their systems from potential exploitation.
The vulnerability affects all supported Windows versions and represents a significant supply chain risk if exploited in defended environments. Therefore, it is imperative for organizations to assess their current Splunk deployments, identify any instances running vulnerable versions, and take immediate action to secure their systems.
Conclusion
The recent identification of these high-severity vulnerabilities in Splunk’s Enterprise and Universal Forwarder products serves as a stark reminder of the ever-present need for vigilance in cybersecurity practices. By promptly applying the necessary patches or mitigation measures, organizations can safeguard their systems against potential privilege escalation attacks and maintain the integrity of their security operations.
