Document Name: NCSA Network Security Policy
Accountable: Adam Slagell
Authors: Adam Slagell, Joerg Heintz, & Mike Dopheide
Approved: <insert date>
NCSA logically divides its network into several different trust zones. Traffic between these zones is monitored by a Network Intrusion Detection System (NIDS), but traffic within a single zone may not be visible to the NIDS. Therefore, systems within a single zone must be trusted and hence hardened to the same level.
These zones can vary significantly in how they are trusted: from networks trusted little more than the general Internet to networks that require stringent vetting and auditing. Most networks are public, but some are very isolated and not even routed. The common requirements across all zones are only that systems follow University security policies and that the Security and Networking teams can quickly identify the location and responsible party for all hosts on our networks.
For the purposes of this document, production systems are defined as any system, to include allocated systems, intended to provide reliable computational and/or data services to a networked constituency. These systems include not only “customer facing” hosts, such as web servers, file servers, login nodes, etc., but also the infrastructure required to support these systems, such as backend database servers, backup and storage systems, authentication servers, etc.
NCSA IT Operations Board
The leaders of ADS (Advanced Digital Services), ITS (Information Technology Systems), and Security are responsible for application of this policy. These three groups are the service providers of infrastructure at NCSA and meet regularly to discuss security issues and strategy for providing better services.
The Security Team is responsible to ensure regular auditing of this policy and automates this when possible. However, responsible does not always mean executing every audit on their own. This is a group endeavor among all the NCSA service providers and requires coordination and cooperation between ADS, ITS and Security.
Violations of this policy may result in immediate disconnection of systems by the Security Team, especially in critical and sensitive zones. Failure to obtain prior approval for installations based on zone policies or attempts to circumvent these policies will be reported to senior management at the NCSA.
For the purposes of this document, production systems are defined as any system, to include allocated systems, intended to provide reliable computational and/or data services to a networked constituency. These systems include not only “customer facing” hosts, such as webservers, file servers, login nodes, etc., but also the infrastructure required to support these systems, such as backend database servers, backup and storage systems, authentication servers, etc.
For any rule or policy, there are likely to be rare exceptions. The NCSA Security Operations team will review and requests sent to them for an exception, and the NCSA CSO will decide whether or not an exception or alternate course of action will be made in response to a request. Appeals to decisions can be made to the Director's Office.
Zone 0: ACB (Academic Computing Building)
This zone hosts all of the hardware that still resides within ACB. This is a temporary zone, needed only until NCSA's external connectivity is switched over to the NPCF and all NCSA systems are moved out of ACB. The general deadline for this is June 30, 2011.
Types of Systems:
The variety of systems in ACB is extensive, but there should be no new systems added to this zone, the exception being replacement of failed hardware on systems still running production services out of ACB. It is requested that teams notify the Security Team when/if production systems are moved from ACB to another building.
- Following best practices (laid out by the NCSA Security Policy) for system security is still necessary as systems that are scheduled to be retired are often overlooked.
- Systems must be updated with all relevant security patches in a timely manner.
- Systems providing production services in ACB must forward their syslogs to the central syslog server, unless impossible, in which case an exception must be requested.
- Retired systems are to be powered off and disconnected from the network.
The NCSA network border is currently at ACB, though ACB will become a stub before July 1, 2011. Traffic into Zone 0 from the outside world is monitored by security taps within ACB with the exception of the 3 dedicated TeraGrid links. Additionally, during the transition, the 10G links between ACB and NPCF will be monitored as an entry point into Zone 1.
Zone 1: High Performance Datacenter
This is the primary zone within the NPCF data center with direct access to significant external bandwidth and no external firewall. The High Perf DC Zone is not appropriate for building new systems and/or configurations until those systems have been fully hardened because most network filtering will be impractical due to sensitivities regarding performance expectations.
Types of Systems:
It is expected that systems within this zone will generally be large HPC systems and their associated data storage hardware, which either require data transfer rates greater than 10 Gb/s or have a sizable physical footprint. While not all systems selected for this zone may match this description, to beplaced in this zone, systems must be approved by the NPCF RAF Space Committee and vetted by the Security Team.
Auditing to ensure systems adhere to these policies will be performed regularly. Given the importance of ensuring each system in this zone is pre-approved to be there, the Security Team will maintain an approved list of systems for this zone and they will be periodically audited.
The Security Team will provide assistance hardening systems; examples include syslog/syslog_ng configurations, Samhain installation, and the building of an instrumented ssh daemon that will be required on most systems. Systems may be removed from the zone if they develop a history of security related issues. Project/administrator history and criticality will be considered with the possibility of a probationary period before systems are reconnected to this zone.
Systems will not be given external network access from this zone until vetted by the Security Team. (1. Group asks RAF committee to house a system in NPCF. 2) They ask neteng for connections and IPs. 3) Neteng gives them access to the test/install zone and refers them to us.) A vetting period of up to one week must be planned for. Systems in this zone and administrators of those systems must:
- restrict network access for unvetted machines;
- Goal: The purpose of this is to prevent new systems from coming up on the network without having been vetted by the Security Team first. MAC registration could actually interfere with failover/redundancy in some cases and may not be ideal for this zone.
- adhere to any service specific requirements spelled-out in the project-specific security plans, such as those developed for Blue Waters;
- follow industry best practices, such as: timely installation of security updates, running minimal services, and removing unnecessary setuid/gid binaries;
- provide a list of expected services to be monitored by the Security Team;
- Goal: This will allow us to define IDS alerts when traffic is seen on an unexpected port or a new service shows up in a network scan.
- provide and maintain an up-to-date list of authorized administrators and/or users to the Security Team;
- Goal: We audit .k5login/sudoers access on a regular basis and this provides a starting point.
- be administrated by full-time employees who have received security training;
- forward logs to the central syslog server;
- Goal: This serves dual purposes. It provides a central location to monitor syslogs as part of our IDS infrastructure, but also serves as a secure backup of syslog data than an attacker cannot modify.
- be configured with the Samhain Host Intrusion Detection System (HIDS) by the Security Team if the machine is publicly addressable;
- Goal: Provides centralized file integrity checking.
- utilize the administrative bastion host with two-factor authentication for access to management interfaces and/or system consoles;
- Goal: Prevent compromised administrator credentials and isolate management services from the public network.
- use strong, non-default passwords or keys for authentication for administrative or service accounts; and
- give access to the system(s) to each security operations user's account in order to quickly investigate security alerts.
- Goal: We investigate alerts 24/7/365. It's inefficient and impractical to wait for system administrators to get back to us given the time sensitivity of most incidents.
All external links into this zone will be monitored, including internal sub-zones and those links to/from other NCSA buildings. Due to financial and physical limitations, traffic completely within this zone cannot be monitored.
Zone 1b: Installation
This defines a type of system-specific zone for systems that are physically located on the floor in 2020 NPCF, but which have not yet met all of the security requirements to be part of the High Performance DC Zone. In most cases, router ACLs would be sufficient for protecting these systems while they are brought online and secured before being moved into Zone 1. These connections will be limited to the extent than they can be monitored via temporary taps or SPAN ports.
Types of Systems:
Systems in this zone may be in the process of initial configuration, but have reached the point of requiring network access to download updates and additional software. As always, to be physically located in the NPCF, systems must be approved by the NPCF RAF Space Committee.
As the purpose of this zone is to provide network access to systems as they are being configured, it's unrealistic to expect them to have a full suite of security tools already configured and working. Packet filtering will allow minimal incoming services to help protect systems that may come with vulnerable software out of the box. These systems must:
- restrict network access until systems are vetted
- use secure, non-default passwords; and
- be hardened according to the requirements for Zone 1 as quickly as possible if the intent is to move the system to that network.
- Systems transitioning to Zone 1 must still be vetted by the Security Team
Zone 2: Testing
NPCF room 2016 is for testing and installing new systems and will reside behind a 1G Firewalled network link. Systems requiring more than 1G bandwidth, but unable to meet a sufficient level of system security to be moved to the High Performance Datacenter zone must provide and connect to the network through a firewall, which must be vetted by security. (In some cases, router ACLs or a NAT could be deemed sufficient.) The firewall(s) will limit traffic both in and out of the test zone and traffic from this network will be monitored. Requests for changes to any firewall configurations should be directed to networking and coordinated with the Security Team.
Types of Systems:
Systems in this zone may be in the process of initial configuration or semi-permanent test systems.
Systems in this zone have the same requirements as those in Zone 1b.
Zone 3a: NCSA Building
The NCSA Building houses the majority of NCSA staff, but also has several small server rooms. With staff and guests moving systems in and out, the networks within this zone are not highly trusted.
It is the goal of the Security Team to eventually be able to separate the NCSA Building into several sub-zones based on logically or physically separate networks. At this time those changes are not feasible and are beyond the scope of this document.
Types of Systems:
A large variety of systems includes staff laptops, workstations, test systems, and may include machines providing production services that, for whatever reason, do not merit or require placement in the NPCF data center.
Traffic within this zone should be regarded with suspicion as these networks are only nominally more trusted than general Internet traffic. As a result, traffic between this zone and the others will be monitored. The Security Team provides assistance with hardening hosts and can provide additional monitoring if requested.
- Production systems (See definition above) in this zone must:
- adhere to security best practices including maintaining security patches, running minimal services, and removing unnecessary setuid binaries;
- provide the Security Team a list of running/listening services;
- maintain a regularly audited list of authorized administrators and/or users;
- use secure, non-default passwords or stronger authentication methods;
- forward syslogs to the central syslog server;
- use a host-based IDS when applicable;
- provide the Security Team with interactive logins to investigate security incidents;
- be located in one of the designated, locked server rooms; and
- must not have wireless network adapters, which could bridge zones, activated; and
- the Security Team will maintain an up-to-date list of these systems
- Goal: For servers and small cluster that may be in the NCSA Building, we want to prevent the currently common occurrence of security finding out about systems after-the-fact.
- Administrators of non-production systems, including workstations and laptops, should:
- install security updates;
- use secure, non-default passwords;
- turn off unneeded services;
- be registered in DNSWorks;
- Goal: Individual workstations and laptops should be registered in order to prevent un-authenticated access to our networks.
- report any suspicious activity to the Security Team; and
- realize that the Security Team can revoke access of any user or system on which a compromise or malicious activity is detected.
Zone 3b: NPCF Offices
The NPCF building houses several offices whose traffic should be handled separately from that of the main datacenter zone. Command Center systems that are not dedicated CnC systems for Zone 1 machines, i.e., networked only to internal subnets, will be treated as members of Zone 3b.
NPCF Office systems share the same security requirements as NCSA Building systems (Zone 3a) but are a separate sub zone because they will be physically monitored at separate points.
Zone 4a: Wireless
NCSA Wireless connectivity is available in all of our buildings (ACB, NCSA & NPCF). For campus wireless networks, all traffic is tunneled outside the NCSA and treated as external traffic. For this reason, they do not fall under any NCSA zone and are not explicitly addressed.
There are both NCSA and University provided wireless networks in the NCSA and the NPCF buildings. These wireless networks are split into multiple logical zones. These networks all have different authentication mechanisms, rules about guest accounts and may or may not utilize link-level encryption. The security requirement for NCSA wireless networks (those that are managed by NCSA or provide NCSA IP addresses) is simply that an adversary gains no additional benefit by physically locating themselves within wireless range of NCSA facilities. For example, by using the strong encryption and authentication technologies of WPA2 or VPNs, it can be reasonably assumed that an attacker already needs a valid Kerberos credential which would give them access to this zone through the VPN anyway.
It is strongly suggested that the UIUC-Guest network be made available in NCSA and NPCF for the use of the majority of visitors and guests. It is also strongly desired that we deprecate the NCSA-Portal network as it potentially gives adversaries additional advantages of proximity.
Types of Systems:
Generally, these systems will be laptops, tablets, and/or smart phones owned by NCSA employees or guests.
Guest laptops are likely candidates for victimization by malicious network traffic, email/web client attacks or viruses. Therefore, the preferred way for guests to obtain Internet access is through the EDURoam, UIUC Public Wifi (where available) or by getting a guest account on UIUCNet, which has good coverage all over campus. These networks are run by CITES and traffic is tunneled outside the NCSA network. Therefore, guest systems would not logically be a part of the NCSA network and would be treated as external Internet traffic.
Requirements that apply to ALL wireless networks in NCSA buildings (whether operated by NCSA or CITES) are:
- wireless networks in NCSA buildings must not give an adversary without NCSA authentication credentials an advantage over simply attacking from the Internet;
- only the NCSA and/or CITES network teams can configure access points and networking hardware for the wireless network -- there will be no rogue or unapproved wireless networks;
- the Security Team will regularly audit/scan for rogue access points; and
- use and configuration of the wireless networks must be compliant with all relevant NCSA and University policies.
Zone 4b: VPN
NCSA offers a VPN service for employees working remotely.
Systems connected to the NCSA VPN networks are treated as external systems with monitoring on the NCSA side of the VPN tunnel.
Zone 5: Blue Waters Management VLANs
Sanitized from this copy
Zone 6: Blue Waters Service VLANs
Sanitized from this copy
Zone 7: Physical Security Systems
This is an island zone only for the NPCF physical security systems.
Types of Systems:
All NPCF physical security systems, and only those systems, are part of this zone. This includes the camera DVRs, the badge readers, the iris scanners, the ACMS workstations (for badging, control and enrollment), and the ACMS database server.
- Devices on this network are on their own physical network, but they are bridged-together private VLANs on shared routers and switches;
- This VLAN is completely private and does not allow for access to or from the outside world, except for occasional VPN access into this zone that is provided to allow the physical security contractors (ITG) to perform maintenance. This VPN access is turned off unless maintenance is being performed; and
- VPN access is also restricted to a small number of remote IP addresses and requires a strong authentication for access.
It should be noted that there will hopefully be a way for alerts to be passed out of this network in the future, but this connection should be unidirectional.
Zone: Island / PSP (Private Sector Program)
This defines a type of zone rather than a specific zone itself. An Island zone has its own, unmonitored external bandwidth either provided by a 3rd party or too large to be monitored by the border NIDS. The island may have an additional, smaller bandwidth connection directly into NPCF zones that will be monitored with the NIDS and treated as external traffic. This includes site-to-site VPN traffic traversing NCSA's external links. This traffic must not be routed inside the NCSA network without also being monitored by a NIDS, and it will be trusted no more than other Internet traffic.
Types of Systems:
These are systems (typically servers) for special projects or private sector partners that bring in their own systems to physically reside in NPCF, but that also require their own external connectivity. Other large systems that have their own pipes, but do not wish to pay for monitoring, can opt for an island zone.
- These zones have their own outside connectivity (preferably non-NCSA IPs), and no direct connection to our network. For the purposes of security monitoring they are treated as external systems;
- If the owners/administrators of systems on this network require security monitoring beyond that provided if/when traffic from these systems crosses into an NCSA network, that monitoring must be coordinated with the Security Team and any additional costs of that monitoring borne by the owners/administrators of the systems.