Unauthenticated Log Injection in Splunk Enterprise

Advisory ID: SVD-2025-1203

CVE ID: CVE-2025-20384

Published: 2025-12-03

Last Update: 2025-12-03

CVSSv3.1 Score: 5.3, Medium

CVSSv3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CWE: CWE-117

Bug ID: VULN-43126

Description

In Splunk Enterprise versions below 10.0.1, 9.4.6, 9.3.8, and 9.2.10, and Splunk Cloud Platform versions below 10.1.2507.4, 10.0.2503.6, and 9.3.2411.117, an unauthenticated attacker can inject American National Standards Institute (ANSI) escape codes into Splunk log files due to improper validation at the /en-US/static/ web endpoint. This may allow them to poison, forge, or obfuscate sensitive log data through specially crafted HTTP requests, potentially impacting log integrity and detection capabilities.

Solution

Upgrade Splunk Enterprise to versions 10.0.1, 9.4.6, 9.3.8, 9.2.10, or higher.

Splunk is actively monitoring and patching Splunk Cloud Platform instances.

Product Status

ProductBase VersionComponentAffected VersionFix Version
Splunk Enterprise10.0Splunk WebBelow 10.0.110.0.1
Splunk Enterprise9.4Splunk Web9.4.0 to 9.4.59.4.6
Splunk Enterprise9.3Splunk Web9.3.0 to 9.3.79.3.8
Splunk Enterprise9.2Splunk Web9.2.0 to 9.2.99.2.10
Splunk Cloud Platform10.1.2507Splunk WebBelow 10.1.2507.410.1.2507.4
Splunk Cloud Platform10.0.2503Splunk WebBelow 10.0.2503.610.0.2503.6
Splunk Cloud Platform9.3.2411Splunk WebBelow 9.3.2411.1179.3.2411.117

Mitigations and Workarounds

The vulnerability affects instances with Splunk Web enabled, turning Splunk Web off is a possible workaround. See Disable unnecessary Splunk Enterprise components and the web.conf configuration specification file for more information on disabling Splunk Web.

Detections

None

Severity

Splunk rates this vulnerability a 5.3, Medium, with a CVSSv3.1 vector of CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Acknowledgments

STÖK / Fredrik Alexandersson