CVE-2024-53247: Splunk Enterprise RCE Vulnerability

CVE-2024-53247 Overview

CVE-2024-53247 is an insecure deserialization vulnerability affecting Splunk Enterprise and the Splunk Secure Gateway app on Splunk Cloud Platform. This vulnerability allows a low-privileged user—one who does not hold the "admin" or "power" Splunk roles—to achieve Remote Code Execution (RCE) on vulnerable systems. The flaw stems from improper handling of serialized objects (CWE-502), enabling attackers with minimal privileges to execute arbitrary code on the target server.

Critical Impact

Low-privileged users can escalate their access to achieve full Remote Code Execution on Splunk Enterprise and Splunk Cloud Platform deployments, potentially compromising sensitive security data and infrastructure.

Affected Products

• Splunk Enterprise versions below 9.3.2
• Splunk Enterprise versions below 9.2.4
• Splunk Enterprise versions below 9.1.7
• Splunk Secure Gateway app versions below 3.4.261 on Splunk Cloud Platform
• Splunk Secure Gateway app versions below 3.7.13 on Splunk Cloud Platform

Discovery Timeline

• 2024-12-10 - CVE-2024-53247 published to NVD
• 2025-01-02 - Last updated in NVD database

Technical Details for CVE-2024-53247

Vulnerability Analysis

This vulnerability is classified as an insecure deserialization flaw (CWE-502). Deserialization vulnerabilities occur when an application accepts serialized data from untrusted sources and reconstructs objects without proper validation. In the context of Splunk Enterprise and Splunk Secure Gateway, this weakness allows attackers to craft malicious serialized payloads that, when processed by the application, execute arbitrary code on the server.

The critical aspect of this vulnerability is that it can be exploited by users with low-privilege accounts. Standard Splunk users who do not possess "admin" or "power" roles can leverage this flaw to bypass authorization controls and achieve code execution. This represents a significant privilege escalation vector, as an attacker with legitimate but limited access can compromise the entire Splunk deployment.

The network-accessible nature of this vulnerability means that any authenticated user with network access to the Splunk instance can potentially exploit it without additional user interaction. This makes it particularly dangerous in enterprise environments where Splunk is often deployed as a centralized logging and security information platform.

Root Cause

The root cause of CVE-2024-53247 is improper deserialization of untrusted data (CWE-502). The affected Splunk components fail to adequately validate or sanitize serialized objects before deserializing them, allowing malicious payloads to be processed. When an attacker supplies a specially crafted serialized object, the deserialization process can instantiate arbitrary classes and execute code embedded within the payload.

Attack Vector

The attack vector for this vulnerability is network-based, requiring only low-privilege authentication. An attacker would need valid credentials for a Splunk user account (even one without administrative privileges) to exploit this vulnerability. The attack does not require user interaction and can be executed directly against the vulnerable endpoint.

The exploitation flow involves:

1. Authenticating to the Splunk instance with any valid user credentials
2. Crafting a malicious serialized payload designed to execute arbitrary commands
3. Submitting the payload to the vulnerable deserialization endpoint
4. The server deserializes the malicious object, triggering code execution

This vulnerability is particularly concerning because Splunk deployments often contain sensitive security logs, authentication data, and may have network access to other critical infrastructure components. Successful exploitation could lead to data exfiltration, lateral movement, or complete infrastructure compromise.

For detailed technical information, refer to the Splunk Security Advisory SVD-2024-1205.

Detection Methods for CVE-2024-53247

Indicators of Compromise

• Unusual process execution originating from Splunk service accounts or processes
• Unexpected network connections from Splunk servers to external or internal hosts
• Creation of new files or scripts in Splunk installation directories
• Suspicious authentication patterns showing low-privilege users accessing administrative functions
• Anomalous serialized data patterns in Splunk application logs

Detection Strategies

• Monitor Splunk internal logs for unusual deserialization errors or exception patterns
• Implement network monitoring to detect unexpected outbound connections from Splunk infrastructure
• Deploy endpoint detection and response (EDR) solutions to identify suspicious process spawning from Splunk services
• Review authentication logs for privilege escalation attempts or unusual user activity patterns
• Configure SIEM rules to alert on post-authentication anomalies involving low-privilege accounts

Monitoring Recommendations

• Enable verbose logging on Splunk Enterprise instances to capture detailed request information
• Implement user behavior analytics to detect deviations from normal access patterns
• Monitor system calls and process creation events on Splunk servers using SentinelOne Singularity
• Establish baseline network behavior for Splunk infrastructure and alert on deviations
• Regularly audit user privileges and access patterns within Splunk deployments

How to Mitigate CVE-2024-53247

Immediate Actions Required

• Upgrade Splunk Enterprise to version 9.3.2, 9.2.4, or 9.1.7 (or later) immediately
• Update Splunk Secure Gateway app to version 3.4.261 or 3.7.13 (or later) on Splunk Cloud Platform
• Review and restrict network access to Splunk instances to authorized users and systems only
• Audit current user accounts and remove unnecessary access privileges
• Monitor for suspicious activity while patching is in progress

Patch Information

Splunk has released security updates to address this vulnerability. Organizations should update to the following minimum versions:

For complete patch details and download links, refer to the Splunk Security Advisory SVD-2024-1205.

Workarounds

• Restrict network access to Splunk management interfaces using firewall rules or network segmentation
• Implement additional authentication controls such as multi-factor authentication (MFA) for Splunk access
• Review and minimize user privileges, ensuring the principle of least privilege is enforced
• Consider temporarily disabling the Splunk Secure Gateway app if not required for operations until patching is complete
• Deploy web application firewall (WAF) rules to filter suspicious serialized data patterns if available

# Example: Restrict Splunk management access via firewall (iptables)
# Allow only specific IP ranges to access Splunk web interface
iptables -A INPUT -p tcp --dport 8000 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 8000 -j DROP

# Verify current Splunk Enterprise version
/opt/splunk/bin/splunk version