A managed security service provider (MSSP) is a third-party entity that offers network security services to an organization, such as firewall operation, administration, monitoring, and maintenance1. A firewall is a device or software that controls the incoming and outgoing network traffic based on predefined rules2. A firewall administrator is a person or entity that manages and maintains the firewall configuration, rules, and policies3. When an organizationuses an MSSP as a firewall administrator, the greatest concern is the exposure of log data, because log data contains sensitive and valuable information about the organization’s network activity, such as source and destination IP addresses, ports, protocols, timestamps, and user identities4. If the log data is not protected properly by the MSSP, it could be accessed, modified, or stolen by unauthorized parties, such as hackers, competitors, or regulators, which could result in data breaches, compliance violations, reputational damage, or legal liabilities for the organization5. The other options are not as concerning as the exposure of log data, because they do not pose a direct and immediate threat to the organization’s data security and privacy, but rather affect the quality and efficiency of the firewall management, as explained below:

B. Lack of governance is a concern when an organization uses an MSSP as a firewall administrator, because it could lead to misalignment or inconsistency between the organization’s and the MSSP’s objectives, policies, and standards for firewall management. However, this concern can be mitigated by establishing a clear and comprehensive service level agreement (SLA) with the MSSP,which defines the roles, responsibilities, expectations, and performance indicators for the firewall management service6.

C. Increased number of firewall rules is a concern when an organization uses an MSSP as a firewall administrator, because it could create complexity, confusion, or duplication in the firewall configuration, which could affect the firewall performance and security. However, this concern can be mitigated by conducting regular firewall audits and reviews with the MSSP, which can help to rationalize, optimize, and update the firewall rules, and to ensure that they are relevant, effective, and efficient for the organization’s network environment.

D. Lack of agreed-upon standards is a concern when an organization uses an MSSP as a firewall administrator, because it could result in gaps or weaknesses in the firewall design and implementation, which could compromise the firewall functionality and security. However, this concern can be mitigated by adopting and following industry best practices, norms, and expectations for firewall management, such as the National Institute of Standards and Technology (NIST) guidelines, the Center for Internet Security (CIS) benchmarks, or the Payment Card Industry Data Security Standard (PCI DSS) requirements . References = Risk and Information Systems Control Study Manual, Chapter 4, Section 4.2.1, page 115. What Is A Managed Security Service Provider (MSSP)? - Fortinet, What is a Firewall? - Definition from Techopedia, Firewall Administrator Job Description - Betterteam, What is a Firewall Log? - Definition from Techopedia, Firewall Log Management: Why It’s Important and How to Do It Right, How to Write a Service Level Agreement (SLA) for an MSSP, [Firewall Auditing: BestPractices for Security and Compliance], [Guidelines on Firewalls and Firewall Policy | CSRC] , [CIS Firewall Benchmark - CIS], [PCI DSS and Firewalls - PCI Security Standards Council]