CVE-2016-6494 in MongoDB
Summary
by MITRE
The client in MongoDB uses world-readable permissions on .dbshell history files, which might allow local users to obtain sensitive information by reading these files.
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Analysis
by VulDB Data Team • 09/24/2024
The vulnerability identified as CVE-2016-6494 affects MongoDB client installations where the .dbshell history file is created with world-readable permissions. This issue represents a classic privilege escalation and information disclosure vulnerability that can have significant implications for database security. The .dbshell file is typically used by MongoDB clients to store command history, making it a potential repository for sensitive information including database connection details, authentication credentials, and administrative commands executed by users. When this file is created with permissions allowing world read access, any local user on the system can access the contents, potentially exposing confidential database operations and access patterns.
The technical flaw stems from improper file permission handling within the MongoDB client implementation. Specifically, the client application fails to set appropriate file system permissions when creating the .dbshell history file, defaulting to overly permissive settings that grant read access to all users on the system. This misconfiguration violates fundamental security principles of least privilege and proper access control. The vulnerability is classified under CWE-732: Incorrect Permission Assignment for Critical Resource, which specifically addresses situations where critical system resources are given insecure permissions that allow unauthorized access. The flaw exists at the application level where file creation operations do not properly implement security-conscious permission settings, making it a direct result of insecure coding practices and inadequate security hardening.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attacks. Local attackers who gain access to the .dbshell history file can extract valuable reconnaissance information including database connection strings, user credentials, and administrative commands that may reveal the structure and operational patterns of the database environment. This information can be leveraged to plan further attacks, identify potential targets for privilege escalation, or even facilitate lateral movement within the network. The vulnerability is particularly concerning in multi-user environments where multiple individuals have local access to the same system, as it creates an unintended information sharing mechanism that can expose sensitive operational data. Additionally, the presence of such information in readable history files may violate compliance requirements for data protection and privacy regulations.
Mitigation strategies for CVE-2016-6494 should focus on immediate permission correction and long-term security hardening practices. The most direct fix involves ensuring that .dbshell history files are created with restrictive permissions, typically limiting access to the owning user only through chmod operations setting permissions to 600 or equivalent. System administrators should implement automated checks to verify that existing .dbshell files have appropriate permissions and correct them if necessary. This vulnerability aligns with ATT&CK technique T1005: Data from Local System, which describes methods attackers use to collect data from compromised systems. Organizations should also consider implementing broader security measures such as regular file system audits, monitoring for unauthorized file access patterns, and ensuring that all database client applications properly implement secure file handling practices. The remediation process should include comprehensive testing to ensure that the fix does not interfere with legitimate user access while maintaining the security of sensitive information stored in these files.