CVE-2023-40596 in Splunk
Summary
by MITRE • 08/30/2023
In Splunk Enterprise versions earlier than 8.2.12, 9.0.6, and 9.1.1, a dynamic link library (DLL) that ships with Splunk Enterprise references an insecure path for the OPENSSLDIR build definition. An attacker can abuse this reference and subsequently install malicious code to achieve privilege escalation on the Windows machine.
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Analysis
by VulDB Data Team • 09/22/2023
The vulnerability identified as CVE-2023-40596 represents a critical privilege escalation flaw within Splunk Enterprise installations running versions prior to 8.2.12, 9.0.6, and 9.1.1 on Windows platforms. This issue stems from an insecure dynamic link library configuration where the OPENSSLDIR build definition references a path that can be manipulated by attackers. The flaw creates a pathway for malicious actors to exploit the system's trust mechanisms and elevate their privileges from standard user level to administrative access.
The technical implementation of this vulnerability involves the manipulation of the dynamic link library loading process within Splunk Enterprise. When the application loads its OpenSSL components, it follows a hardcoded path that points to a location which can be compromised. This insecure path reference allows attackers to place malicious DLL files in the specified directory structure, which will then be loaded automatically by the legitimate Splunk processes. The vulnerability specifically affects Windows environments where the default installation paths can be manipulated to include attacker-controlled code. This type of flaw falls under the CWE-427 Uncontrolled Search Path Element category, where the application's search path contains elements that can be influenced by an attacker.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with a persistent foothold within the compromised system. Once elevated privileges are obtained, attackers can access sensitive data, modify system configurations, install additional malware, or establish backdoors for continued access. The vulnerability is particularly concerning because it affects the core Splunk Enterprise application that many organizations rely on for security monitoring and log analysis, potentially allowing attackers to remain undetected while compromising the very systems designed to detect malicious activity.
Mitigation strategies for CVE-2023-40596 should prioritize immediate patching of affected Splunk Enterprise installations to the recommended versions 8.2.12, 9.0.6, or 9.1.1 where the insecure path references have been corrected. Organizations should also implement additional security controls including monitoring for unauthorized DLL loading activities, restricting write permissions to critical system directories, and conducting regular security assessments of installed software components. The ATT&CK framework categorizes this vulnerability under T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation, highlighting the need for comprehensive endpoint detection and response capabilities. Network segmentation and principle of least privilege access controls should be enforced to limit the potential damage from successful exploitation, while regular security awareness training can help prevent initial compromise through social engineering or other attack vectors.