CVE-2023-40592
📋 TL;DR
This CVE describes a reflected cross-site scripting (XSS) vulnerability in Splunk Enterprise's /app/search/table endpoint. Attackers can craft malicious web requests to execute arbitrary commands on vulnerable Splunk instances. Organizations running Splunk Enterprise versions below 9.1.1, 9.0.6, or 8.2.12 are affected.
💻 Affected Systems
- Splunk Enterprise
📦 What is this software?
Splunk by Splunk
Splunk by Splunk
Splunk by Splunk
⚠️ Risk & Real-World Impact
Worst Case
Full compromise of the Splunk instance leading to data exfiltration, lateral movement within the network, and potential ransomware deployment.
Likely Case
Session hijacking, credential theft, and unauthorized access to sensitive log data stored in Splunk.
If Mitigated
Limited impact with proper input validation and output encoding preventing successful exploitation.
🎯 Exploit Status
Reflected XSS typically requires user interaction but can be delivered via phishing or malicious links.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 9.1.1, 9.0.6, or 8.2.12
Vendor Advisory: https://advisory.splunk.com/advisories/SVD-2023-0801
Restart Required: Yes
Instructions:
1. Backup Splunk configuration and data. 2. Download appropriate patched version from Splunk website. 3. Stop Splunk services. 4. Install update following Splunk upgrade documentation. 5. Restart services and verify functionality.
🔧 Temporary Workarounds
Web Application Firewall (WAF)
allDeploy WAF rules to block malicious requests targeting the /app/search/table endpoint
Input Validation Filter
allImplement custom input validation for the vulnerable endpoint
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) headers to prevent script execution
- Restrict network access to Splunk web interface using firewall rules
🔍 How to Verify
Check if Vulnerable:
Check Splunk version via web interface or command line: splunk versionCheck Version:
splunk versionVerify Fix Applied:
Verify version is 9.1.1, 9.0.6, 8.2.12 or higher and test endpoint with XSS payloads📡 Detection & Monitoring
Log Indicators:
- Unusual requests to /app/search/table with script tags or JavaScript payloads
- Multiple failed login attempts following suspicious web requests
Network Indicators:
- HTTP requests containing malicious script payloads in parameters
- Traffic patterns showing exploitation attempts
SIEM Query:
index=_internal sourcetype=splunkd_access uri="/app/search/table*" | search *script* OR *javascript* OR *onload* OR *onerror*