Overview
CVE-2025-20384 is a medium-severity vulnerability affecting Splunk Enterprise and Splunk Cloud Platform. This security flaw allows an unauthenticated attacker to inject American National Standards Institute (ANSI) escape codes into Splunk log files. Due to improper validation at the /en-US/static/ web endpoint, specially crafted HTTP requests can be used to poison, forge, or obfuscate sensitive log data. This could significantly impact log integrity and detection capabilities, potentially masking malicious activity.
Technical Details
The vulnerability stems from insufficient input validation at the /en-US/static/ web endpoint in Splunk. This allows an attacker to send HTTP requests containing ANSI escape codes. These escape codes, normally used for text formatting in terminals, can be injected into the Splunk logs. Because Splunk processes and renders these codes, attackers can manipulate the displayed log data. The lack of proper sanitization before writing to the logs is the root cause of the issue.
CVSS Analysis
This vulnerability has been assigned a CVSS score of 5.3 (Medium).
- CVSS Vector: (Available on the Splunk advisory)
- Explanation: The CVSS score reflects the potential for unauthorized modification of log data, which can undermine security monitoring and incident response efforts. While the vulnerability doesn’t directly grant system access, the ability to manipulate logs is a significant security concern.
Possible Impact
The successful exploitation of CVE-2025-20384 can lead to the following impacts:
- Log Poisoning: Attackers can inject misleading or false information into the logs, making it difficult to identify genuine security incidents.
- Log Forgery: Malicious actors can create fabricated log entries to cover their tracks or implicate others.
- Log Obfuscation: Sensitive log data can be hidden or rendered unreadable, hindering security investigations.
- Compromised Security Monitoring: The integrity of security monitoring systems that rely on Splunk logs can be compromised, leading to delayed or missed detections of malicious activity.
Mitigation and Patch Steps
To mitigate the risk associated with CVE-2025-20384, it is crucial to upgrade your Splunk installation to one of the following versions or later:
- Splunk Enterprise: 10.0.1, 9.4.6, 9.3.8, or 9.2.10
- Splunk Cloud Platform: 10.1.2507.4, 10.0.2503.6, or 9.3.2411.117.125
Follow the official Splunk upgrade documentation for detailed instructions on how to perform the upgrade safely and effectively. Regularly monitor Splunk’s security advisories for any new vulnerabilities and apply necessary patches promptly.
