CVE-2023-37469 in CasaOS
Summary
by MITRE • 08/25/2023
CasaOS is an open-source personal cloud system. Prior to version 0.4.4, if an authenticated user using CasaOS is able to successfully connect to a controlled SMB server, they are able to execute arbitrary commands. Version 0.4.4 contains a patch for the issue.
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Analysis
by VulDB Data Team • 08/25/2023
The vulnerability identified as CVE-2023-37469 affects CasaOS, an open-source personal cloud system designed to provide users with a comprehensive platform for managing personal data and services. This system serves as a bridge between users and various network resources, including file sharing protocols such as Server Message Block. The flaw exists in versions prior to 0.4.4, creating a critical security risk for users who rely on CasaOS for their personal cloud infrastructure. The vulnerability stems from insufficient input validation and sanitization mechanisms within the SMB connection handling process, allowing authenticated users to exploit a command injection flaw.
The technical nature of this vulnerability aligns with CWE-77 and CWE-94, representing command injection flaws that enable attackers to execute arbitrary code on the affected system. When an authenticated user successfully establishes a connection to a controlled SMB server, the system fails to properly validate or sanitize the SMB server response data. This oversight allows the malicious SMB server to inject commands that CasaOS executes with the privileges of the authenticated user. The vulnerability demonstrates a classic path traversal and command execution pattern where user-controllable input flows directly into system command invocations without adequate security controls.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with a potential foothold for broader system compromise. An authenticated user who gains control of an SMB server can execute commands with the same privileges as the CasaOS service, potentially leading to data exfiltration, system modification, or lateral movement within the network. The attack vector requires authentication, which limits the exposure to authorized users, but once exploited, the impact can be severe. This vulnerability particularly affects users who operate CasaOS in environments where they might have legitimate SMB connections or where SMB servers are exposed to untrusted networks, creating a dangerous scenario for personal cloud deployments.
Mitigation strategies should focus on immediate patch deployment to version 0.4.4 or later, which includes proper input validation and sanitization mechanisms for SMB connections. System administrators should also implement network segmentation to limit SMB access to trusted networks and consider implementing network monitoring to detect suspicious SMB traffic patterns. The principle of least privilege should be enforced by ensuring CasaOS operates with minimal required permissions and that SMB connections are only established with verified and trusted servers. Additionally, regular security audits of CasaOS configurations and network access controls should be conducted to maintain security posture against similar vulnerabilities. Organizations should also consider implementing the ATT&CK framework's T1059.001 technique detection for command and scripting interpreter usage, as this vulnerability essentially enables an attacker to leverage command execution capabilities through SMB protocol interactions.