Created: 6/15/19
Updated: 11/27/19
Below are some basic “Secure-by-Design” recommendations that should be followed to ensure a “Secure-by-Design” Defense-in-Depth:
This list is not all inclusive, but it’s a good baseline.
- Digital forms of configurations that can be stored encrypted and highly available
- Avoid Telnet, FTP or other forms of communication sent in clear text
- Secure management protocols such as SSH, and TLS 1.2 or higher for in-motion traffic
- Blocked UDP 3544, unless otherwise needed for IPv6
- Blocked TCP 53, 88, 135-139, 445 and UDP 88, 137, 138 on all public WAN zoned firewalls, when possible – Wannacry mitigation
- Allow only UDP 53 and TCP 80, 443, and 3389 (if using default)
- Change RDP port from default 3389 for all critical servers, especially public facing servers. Example: here.
- Access control lists for all critical servers
- Controlled access thru ACL’s such as ACL’d Jumpboxes
- Out-of-band Management Fabric, not in-band, think vLAN hopping or double tagging, when possible (cost restraints)
- Consider moving native vLAN from default vLAN to high unused vLAN, prevents double tagging
- Out-of-band Storage Fabric, think is encryption of iSCSI a good idea? – if your arrays can’t handle the encryption overhead put them OOB of production traffic in a secured data rack
- Enable complex passwords on SSH, Telnet, and Console line access on network switches
- Enable port security with sticky macs on ports with shutdown violations, when possible
- Disable unused ports on switches, when possible
- Disable dynamic auto-negotiation trunking protocols on switch ports, this prevents unauthorized probing
- Enable Routing authentication between switches and firewalls of Advanced routing like OSPF with HMAC-SHA-256 or higher, when possible. Don’t use MD5 or HMAC-SHA-1
- Deployment of 802.1X aka PNAC, when possible
- Deployment of 2FA on all forms of business, critical systems are of upmost importance 1st like email, remote access, documentation then servers and desktops.
- Ensure a comprehensive backup plans is deployed, 3-2-1 is recommended: 3 places of backups, two local, and one cloud; one being the file server or storage appliance, one being a local backup array, and the other being a cloud backup array and then ensure encryption is applied and backups are tested monthly
- Recommended minimum backup routine (1) last Saturday of each month ‘grandfather’ backup, (4) weekly Saturday ‘father’ backups, and (5) weekly ‘son’ backups (cycled weekly) for 1 month
- Implementation of “In-Motion” Encryption; article on topic, here.
- Implementation of AES-256 bit encryption on storage arrays including backup arrays for data at-rest
- Highly available storage of Storage “At-Rest” Encryption keys for both local (iSCSI/FC/FCoe NAS/SAN) storage and local/cloud backup arrays
- Determine if Bitlocker Encryption is a viable solution for DLP, applies only to Windows Systems, use if possible (note be mindful of O/S version with Bitlocker)
- Ensure Bitlocker Encryption keys are stored highly-available, if applicable
- All updates for server, switches, firewall, etc and firmware’s should be digitally signed and verified against their hash after downloading and before executing
- Apply all security updates possible for servers and stagger other updates as needed, at a minimum
- Use TPM v1.2 or higher chips
- Secured document management for all passwords and configurations stored with high-availability
- Audit and logging on all users, desktops, servers, switches, firewalls, and other network devices
- Least privileged of system and file access
- Command shell restrictions, example blocking command prompt for standard users via group policy
- When sharing folders determine if adding a $, example “foldername$” at end of folder share should be configured, this prevents folder share from being visible to standard users when navigating SMB UNC mappings
- Remove bloatware from desktops and servers provide from computer maker by default, exploits have been found with bloatware from Dell OpenManage as an example.
- All executable programs require administrator permissions to install on all accounts, especially on IT admin accounts
- Standard user logins for all users to “live” in, including IT admins
- Administrator accounts made with complex passwords of 20+ characters that are used to “elevation” even by IT administrators
- Removable media turned off by group policy
- Deployment of web cam covers
- Enforcement of only encrypted flash drives used
- Auto logoff of users after 3 minutes of inactivity via group policy
- Enforcement of complex and unique passwords with long lengths of 15+ charterers made up of words vs the traditional shorter passwords with symbols, upper case, lower case, and numbers
- Balancing of Windows Server Active Directory FSMO Masters. Example: here.
- When a PKI is used, create the root CA in a standalone deployment as a member of a custom workgroup, not domain joined. Once Enterprise Intermediate CA is online, turn off root CA and keep offline unless to do system update quarterly
- Ensure that DNS “zone transfers are only allowed on Name Server for the specified domain” only.
- Manually add a rule for NTP servers like pool.ntp.org over UDP port 123 as the only allowed NTP server’s to connect to your network; as an example. Also ensure your PDC FSMO Master only uses these NTP servers for time. Examples: here, and here.
- Use of PKI certificates, when possible
- Acceptable Use Policy
- Clean Desk Policy
- Email Policy
- Social Media “Information Sharing” Policy
- Acceptable Data Encryption Policy
- Data Loss Prevention Policy
- Removable Media Policy
- End User Password Complexity Policy
- Anti Virus and Anti-Malware Policy
- Data Logging Policy
- Internet Usage Policy
- Edge Firewall Policy
- Server Room Access Policy
- Server Security Policy
- Audit Policy
- Mobile Device Encryption Policy
- Software Installation Policy
- Equipment Disposal Policy
- Workstation Security Policy (If HIPPA Compliant)
- Remote Access Policy
- Router and Switch Security Policy
- Wireless Communications Policy
- Digital Signature Acceptance Policy
- Security Awareness Training Policy
- Disaster Recovery Plan Policy
- Security Response Plan Policy
- Data Breach Response Policy
This list will be updated over time.
Refer to NIST 800-54 Rev 4
Cheers! 😀