CVE-2023-32714: Splunk Path Traversal Vulnerability

CVE-2023-32714 Overview

CVE-2023-32714 is a path traversal vulnerability affecting the Splunk App for Lookup File Editing versions below 4.0.1. A low-privileged user can exploit this vulnerability by sending a specially crafted web request to trigger a path traversal attack, allowing unauthorized read and write access to restricted areas of the Splunk installation directory.

Critical Impact

Low-privileged attackers can read and write to restricted Splunk installation directories, potentially compromising the integrity and confidentiality of the Splunk deployment.

Affected Products

• Splunk App for Lookup File Editing versions below 4.0.1
• Splunk Enterprise 8.1.x versions below 8.1.14
• Splunk Enterprise 8.2.x versions below 8.2.11
• Splunk Enterprise 9.0.x versions below 9.0.5

Discovery Timeline

• 2023-06-01 - CVE-2023-32714 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-32714

Vulnerability Analysis

This vulnerability is classified under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) and CWE-35 (Path Traversal). The flaw exists within the Splunk App for Lookup File Editing, which fails to properly sanitize user-supplied input in web requests related to file operations.

When a low-privileged user sends a malicious request containing path traversal sequences (such as ../), the application does not adequately validate or restrict the file path, allowing the attacker to escape the intended directory boundary. This enables access to files and directories outside the designated lookup file storage location within the Splunk installation.

The vulnerability can be exploited remotely over the network and requires only low-level privileges, making it accessible to any authenticated user with basic access to the Splunk environment.

Root Cause

The root cause of this vulnerability is insufficient input validation and path canonicalization in the file handling routines of the Splunk App for Lookup File Editing. The application accepts user-controlled file path parameters without properly sanitizing directory traversal sequences, allowing attackers to reference files outside the intended scope.

The lack of proper path normalization and boundary enforcement enables specially crafted requests to bypass the intended directory restrictions, granting unauthorized access to sensitive Splunk configuration files and system resources.

Attack Vector

The attack is conducted over the network by an authenticated user with low privileges. The attacker crafts a malicious HTTP request targeting the lookup file editing functionality, embedding path traversal sequences within the file path parameter.

By manipulating the file path (e.g., using sequences like ../../etc/passwd or ..\..\system\local\server.conf), the attacker can traverse outside the intended lookup directory and access or modify sensitive files within the Splunk installation hierarchy. This could include configuration files, credentials, or other sensitive data stored on the Splunk server.

The attack requires no user interaction and can be performed with network access to the vulnerable Splunk instance. For detailed technical analysis, refer to the Splunk Security Advisory SVD-2023-0608 and the Splunk Research Application Analysis.

Detection Methods for CVE-2023-32714

Indicators of Compromise

• Web server logs containing requests to the Lookup File Editing app endpoints with path traversal sequences (../, ..%2f, ..%5c)
• Unexpected file access or modification events in restricted Splunk directories
• Audit logs showing low-privileged users accessing files outside the $SPLUNK_HOME/etc/apps/lookup_editor/lookups/ directory
• Anomalous read/write activity in Splunk system configuration directories by non-administrative accounts

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block requests containing path traversal patterns
• Monitor Splunk internal logs for suspicious file access patterns originating from the Lookup File Editing app
• Deploy Splunk's own detection analytic available at the Splunk Research repository
• Review authentication logs for low-privileged accounts exhibiting unusual file access behavior

Monitoring Recommendations

• Enable detailed audit logging for file system operations within the Splunk installation directory
• Configure alerts for HTTP requests containing encoded or plain-text directory traversal sequences targeting Splunk endpoints
• Regularly review access logs for the Splunk App for Lookup File Editing for anomalous patterns
• Implement file integrity monitoring on critical Splunk configuration directories

How to Mitigate CVE-2023-32714

Immediate Actions Required

• Upgrade the Splunk App for Lookup File Editing to version 4.0.1 or later immediately
• Upgrade Splunk Enterprise to version 8.1.14, 8.2.11, or 9.0.5 depending on your release branch
• Review access logs for signs of exploitation prior to patching
• Audit user privileges and restrict access to the Lookup File Editing app to only necessary personnel

Patch Information

Splunk has released version 4.0.1 of the Splunk App for Lookup File Editing to address this vulnerability. Additionally, users should ensure their Splunk Enterprise installation is updated to a patched version:

• Splunk Enterprise 8.1.x: Upgrade to 8.1.14 or later
• Splunk Enterprise 8.2.x: Upgrade to 8.2.11 or later
• Splunk Enterprise 9.0.x: Upgrade to 9.0.5 or later

For complete patch details and download instructions, see the Splunk Security Advisory SVD-2023-0608.

Workarounds

• Disable or remove the Splunk App for Lookup File Editing until patching is possible
• Restrict network access to the Splunk web interface to trusted IP addresses only
• Implement strict role-based access controls to limit which users can access the Lookup File Editing functionality
• Deploy a reverse proxy or WAF with rules to block path traversal attempts

# Configuration example - Restrict access to Lookup Editor app in authorize.conf
# Add to $SPLUNK_HOME/etc/system/local/authorize.conf

[role_admin]
importRoles = user
srchIndexesAllowed = *
srchIndexesDefault = main
# Only admin role should access lookup_editor
capabilities = admin_all_objects

[role_user]
# Remove lookup_editor access from regular users
srchIndexesAllowed = main
srchIndexesDefault = main