Disable or Remove Feature or Program: Disable or remove unnecessary and potentially vulnerable software, features, or services to reduce the attack surface and prevent abuse by adversaries. This involves identifying software or features that are no longer needed or that could be exploited and ensuring they are either removed or properly disabled. This mitigation can be implemented through the following measures:
Remove Legacy Software:
- Use Case: Disable or remove older versions of software that no longer receive updates or security patches (e.g., legacy Java, Adobe Flash).
- Implementation: A company removes Flash Player from all employee systems after it has reached its end-of-life date.
Disable Unused Features:
- Use Case: Turn off unnecessary operating system features like SMBv1, Telnet, or RDP if they are not required.
- Implementation: Disable SMBv1 in a Windows environment to mitigate vulnerabilities like EternalBlue.
Control Applications Installed by Users:
- Use Case: Prevent users from installing unauthorized software via group policies or other management tools.
- Implementation: Block user installations of unauthorized file-sharing applications (e.g., BitTorrent clients) in an enterprise environment.
Remove Unnecessary Services:
- Use Case: Identify and disable unnecessary default services running on endpoints, servers, or network devices.
- Implementation: Disable unused administrative shares (e.g., C$, ADMIN$) on workstations.
Restrict Add-ons and Plugins:
- Use Case: Remove or disable browser plugins and add-ons that are not needed for business purposes.
- Implementation: Disable Java and ActiveX plugins in web browsers to prevent drive-by attacks.
Privileged Account Management: Privileged Account Management focuses on implementing policies, controls, and tools to securely manage privileged accounts (e.g., SYSTEM, root, or administrative accounts). This includes restricting access, limiting the scope of permissions, monitoring privileged account usage, and ensuring accountability through logging and auditing.This mitigation can be implemented through the following measures:
Account Permissions and Roles:
- Implement RBAC and least privilege principles to allocate permissions securely.
- Use tools like Active Directory Group Policies to enforce access restrictions.
Credential Security:
- Deploy password vaulting tools like CyberArk, HashiCorp Vault, or KeePass for secure storage and rotation of credentials.
- Enforce password policies for complexity, uniqueness, and expiration using tools like Microsoft Group Policy Objects (GPO).
Multi-Factor Authentication (MFA):
- Enforce MFA for all privileged accounts using Duo Security, Okta, or Microsoft Azure AD MFA.
Privileged Access Management (PAM):
- Use PAM solutions like CyberArk, BeyondTrust, or Thycotic to manage, monitor, and audit privileged access.
Auditing and Monitoring:
- Integrate activity monitoring into your SIEM (e.g., Splunk or QRadar) to detect and alert on anomalous privileged account usage.
Just-In-Time Access:
- Deploy JIT solutions like Azure Privileged Identity Management (PIM) or configure ephemeral roles in AWS and GCP to grant time-limited elevated permissions.
Tools for Implementation
Privileged Access Management (PAM):
- CyberArk, BeyondTrust, Thycotic, HashiCorp Vault.
Credential Management:
- Microsoft LAPS (Local Admin Password Solution), Password Safe, HashiCorp Vault, KeePass.
Multi-Factor Authentication:
- Duo Security, Okta, Microsoft Azure MFA, Google Authenticator.
Linux Privilege Management:
- sudo configuration, SELinux, AppArmor.
Just-In-Time Access:
- Azure Privileged Identity Management (PIM), AWS IAM Roles with session constraints, GCP Identity-Aware Proxy.
Network Segmentation: Network segmentation involves dividing a network into smaller, isolated segments to control and limit the flow of traffic between devices, systems, and applications. By segmenting networks, organizations can reduce the attack surface, restrict lateral movement by adversaries, and protect critical assets from compromise.
Effective network segmentation leverages a combination of physical boundaries, logical separation through VLANs, and access control policies enforced by network appliances like firewalls, routers, and cloud-based configurations. This mitigation can be implemented through the following measures:
Segment Critical Systems:
- Identify and group systems based on their function, sensitivity, and risk. Examples include payment systems, HR databases, production systems, and internet-facing servers.
- Use VLANs, firewalls, or routers to enforce logical separation.
Implement DMZ for Public-Facing Services:
- Host web servers, DNS servers, and email servers in a DMZ to limit their access to internal systems.
- Apply strict firewall rules to filter traffic between the DMZ and internal networks.
Use Cloud-Based Segmentation:
- In cloud environments, use VPCs, subnets, and security groups to isolate applications and enforce traffic rules.
- Apply AWS Transit Gateway or Azure VNet peering for controlled connectivity between cloud segments.
Apply Microsegmentation for Workloads:
- Use software-defined networking (SDN) tools to implement workload-level segmentation and prevent lateral movement.
Restrict Traffic with ACLs and Firewalls:
- Apply Access Control Lists (ACLs) to network devices to enforce "deny by default" policies.
- Use firewalls to restrict both north-south (external-internal) and east-west (internal-internal) traffic.
Monitor and Audit Segmented Networks:
- Regularly review firewall rules, ACLs, and segmentation policies.
- Monitor network flows for anomalies to ensure segmentation is effective.
Test Segmentation Effectiveness:
- Perform periodic penetration tests to verify that unauthorized access is blocked between network segments.