Ensure there is no unrestricted inbound access to TCP port 4333 (mSQL)

Security & Compliance
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TCP port 4333 is used by mSQL database management system to allow client-server communication. If this port is left open and unrestricted, it can allow unauthorized access to the database and its contents, leading to potential data breaches and loss of sensitive information. Therefore, it is important to ensure that there is no unrestricted inbound access to TCP port 4333 to protect the mSQL server from attacks and unauthorized access.


To remediate the issue of unrestricted inbound access to TCP port 4333 (mSQL), follow these steps:

  1. Identify the security group(s) associated with the affected instance(s) that have unrestricted inbound access to port 4333.
  2. Edit the security group rules to restrict access to only authorized IP addresses or CIDR ranges.
  3. If necessary, create a new security group that allows access to port 4333 only from authorized IP addresses or CIDR ranges, and associate the affected instance(s) with this new security group.
  4. If the affected instance(s) are part of an Auto Scaling group, update the launch configuration to associate the new or updated security group.
  5. Test connectivity to port 4333 from authorized IP addresses or CIDR ranges to ensure that the necessary access is still available, while all other traffic is blocked.
  6. Monitor the security group rules to ensure that no unauthorized changes are made that could reintroduce the issue.
Enforced Resources
Note: Remediation steps provided by Lightlytics are meant to be suggestions and guidelines only. It is crucial to thoroughly verify and test any remediation steps before applying them to production environments. Each organization's infrastructure and security needs may differ, and blindly applying suggested remediation steps without proper testing could potentially cause unforeseen issues or vulnerabilities. Therefore, it is strongly recommended that you validate and customize any remediation steps to meet your organization's specific requirements and ensure that they align with your security policies and best practices.