How do you secure your Python REST API against common vulnerabilities?

Avoid storing tokens in cookies. If you must use cookies for storing JWTs, implement CSRF tokens. A CSRF token is a unique, secret, and unpredictable value that is generated by the server and sent to the client. This token must be included in any state-changing request, typically as a custom header or in the body of the request.

On login, generate a JWT for the user. The token should include essential user information and an expiration date. Set the token expiration time according to your security requirements. Clients should include the JWT in the HTTP Authorization header for each request. Verify the token to ensure it is valid and not expired. Decode the token to extract user information. Implement careful management of token expiration. Consider mechanisms for token refresh if the application requires long-lived sessions. If your application uses roles, implement an Access Control List for the API. Ensure that the tokens grant access only to the endpoints related to the user's roles.

Strict Content-Type and Input Types: Ensure that your API endpoints only accept the expected content types (e.g., application/json for JSON payloads). This can prevent certain types of attacks where the content type is manipulated. Limit Input Length and Size: Restrict the length and size of user inputs to avoid denial of service (DoS) attacks and excessive resource consumption. For example, limit the length of strings and the overall size of request bodies.

Implement short-lived tokens to minimize the impact of a stolen token. Use refresh tokens to maintain user sessions without requiring frequent re-authentication.

Least Privilege Principle: Always apply the principle of least privilege, granting users only the permissions they need to perform their tasks. Avoid giving broader access than necessary. Token Claims for Roles: Embed roles and permissions within JWT claims to streamline access control checks. This allows you to efficiently verify user roles and permissions without additional database queries. Audit and Logging: Implement logging to audit access to your API endpoints. This helps in tracking and reviewing access patterns, detecting unauthorized access attempts, and improving security measures.

I would also say that for cyber security audits, maintain logs of access granted. This will help if there is an incident to see why a certain access was granted to a person and will also be beneficial for any insurance claims in case of an incident.

Encryption Key Management: Properly manage your encryption keys. Use a secure key management service (KMS) like AWS KMS, Google Cloud KMS, or HashiCorp Vault to store and rotate keys securely. Regular Security Audits: Regularly audit your encryption implementations to ensure they meet current security standards and best practices. Update your encryption algorithms and protocols as necessary to address new vulnerabilities.

Logging is a must. However monitoring the logs on regular bases and making decisions on them in iterative way makes it ironclad. To be able to determine what is about to be broken into rather than forensics on what is broken into is far more valuable to company’s survival. Adding those alerts to communication channels such as slack is also worthwhile effort.