CVE-2019-4000 in inSync Mac OS Client
Summary
by MITRE
Improper neutralization of directives in dynamically evaluated code in Druva inSync Mac OS Client 6.5.0 allows a local, authenticated attacker to execute arbitrary Python expressions with root privileges.
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Analysis
by VulDB Data Team • 04/06/2024
The vulnerability identified as CVE-2019-4000 represents a critical security flaw in the Druva inSync Mac OS Client version 6.5.0 that stems from improper handling of directives within dynamically evaluated code. This issue creates a path for local authenticated attackers to execute arbitrary Python expressions with elevated root privileges, fundamentally undermining the client's security model and potentially compromising the entire system. The flaw specifically resides in how the application processes and evaluates dynamic code directives, failing to properly sanitize or neutralize potentially malicious input that could be injected by an attacker with local access.
The technical implementation of this vulnerability manifests through the client's failure to adequately validate or escape input parameters that are subsequently processed through Python's dynamic evaluation mechanisms. When an authenticated user with local access manipulates specific input fields or parameters within the application's interface, the system's insufficient sanitization allows attacker-controlled code to be executed within the context of the application's runtime environment. This improper neutralization of directives directly maps to CWE-94, which describes the weakness of allowing arbitrary code execution through the improper handling of dynamically evaluated code. The vulnerability's exploitation requires local authentication, making it particularly dangerous in environments where users may have elevated privileges or where privilege escalation is possible through other vectors.
The operational impact of CVE-2019-4000 extends beyond simple code execution, as the attacker gains root privileges through this vulnerability, enabling complete system compromise. This elevated access level allows for persistent backdoor installation, data exfiltration, system monitoring, and further lateral movement within the network. The Mac OS environment presents unique challenges for exploitation due to the system's security model, including Gatekeeper, System Integrity Protection, and code signing requirements, yet this vulnerability bypasses these protections by leveraging the legitimate application's execution context. The attack vector's requirement for local authentication provides some protection against remote exploitation, but local access is often achievable through various means including physical access, social engineering, or exploitation of other vulnerabilities that may provide initial foothold.
Security professionals should implement comprehensive mitigations addressing both immediate and long-term protection strategies for this vulnerability. The most effective immediate solution involves updating the Druva inSync Mac OS Client to versions that properly address the code evaluation flaw, ensuring that all input directives are properly sanitized and validated before processing. Organizations should also implement strict access controls and monitoring of local user activities, particularly focusing on any unusual Python execution patterns or unauthorized application modifications. The vulnerability's alignment with ATT&CK technique T1059.006 for Python execution and T1068 for local privilege escalation highlights the importance of monitoring for these specific attack patterns. Additionally, system administrators should consider implementing additional layers of protection including application whitelisting, file integrity monitoring, and regular security audits to detect potential exploitation attempts and ensure that the updated client versions are properly deployed across all affected systems.