Securing MongoDB involves a multi-faceted approach, encompassing various aspects of database deployment, configuration, access control, and more. Let's delve into some common vulnerabilities and ways to mitigate them: 

• Default Configuration: MongoDB's default settings may not be suitable for a production environment. Change the default configuration to ensure proper security settings, such as network binding, authentication, and authorization. 
• Weak Authentication: Always enable authentication to ensure only authorized users can access the database. Use strong passwords, enforce password policies, and consider multi-factor authentication for enhanced security. 
• Inadequate Authorization: MongoDB provides role-based access control (RBAC) to restrict users' actions. Define roles with the least privilege principle, ensuring users can only perform actions necessary for their tasks. 
• Data Exposure: Implement encryption, both at rest and in transit, to protect sensitive data from unauthorized access. Utilize SSL/TLS for encrypting data in transit and enable MongoDB's native encryption options for data at rest. 
• Injection Attacks: Prevent injection attacks by sanitizing user inputs and using parameterized queries. Avoid building queries directly from user inputs to minimize the risk of data manipulation attacks. 
• Unrestricted Queries: Be cautious when executing queries. Limit the use of the `$where` operator, which can execute arbitrary JavaScript code, and employ query whitelisting to ensure only approved queries are executed.