Chapter 10: Operational Security Security+ Guide to Network Security Fundamentals Second Edition Instructor by Sukchatri PRASOMSUK

2 Objectives Harden physical security with access controls Minimize social engineering Secure the physical environment Define business continuity Plan for disaster recovery

3 Hardening Physical Security with Access Controls Adequate physical security is one of the first lines of defense against attacks Protects equipment and the infrastructure itself Has one primary goal: to prevent unauthorized users from reaching equipment to use, steal, or vandalize

4 Hardening Physical Security with Access Controls (continued) Configure an operating system to enforce access controls through an access control list (ACL), a table that defines the access rights each subject has to a folder or file Access control also refers to restricting physical access to computers or network devices

5 Controlling Access with Physical Barriers Most servers are rack-mounted servers A rack-mounted server is 175 inches (445 cm) tall and can be stacked with up to 50 other servers in a closely confined area Rack-mounted units are typically connected to a KVM (keyboard, video, mouse) switch, which in turn is connected to a single monitor, mouse, and keyboard

6 Controlling Access with Physical Barriers (continued)

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8 In addition to securing a device itself, you should also secure the room containing the device Two basic types of door locks require a key: –A preset lock (key-in-knob lock) requires only a key for unlocking the door from the outside –A deadbolt lock extends a solid metal bar into the door frame for extra security To achieve the most security when using door locks, observe the good practices listed on pages 345 and 346 of the text

9 Controlling Access with Physical Barriers (continued) Cipher locks are combination locks that use buttons you push in the proper sequence to open the door Can be programmed to allow only the code of certain people to be valid on specific dates and times Basic models can cost several hundred dollars each while advanced models can run much higher Users must be careful to conceal which buttons they push to avoid someone seeing the combination (shoulder surfing)

10 Controlling Access with Physical Barriers (continued) Other physical vulnerabilities should be addressed, including: –Suspended ceilings –HVAC ducts –Exposed door hinges –Insufficient lighting –Dead-end corridors

11 Controlling Access with Biometrics Biometrics uses a person’s unique characteristics to authenticate that person Some human characteristics used for identification include fingerprint, face, hand, iris, retina, and voice Many high-end biometric scanners are expensive, can be difficult to use, and can produce false positives (accepting unauthorized users) or false negatives (restricting authorized users)

12 Minimizing Social Engineering The best defenses against social engineering are a strong security policy along with adequate training An organization must establish clear and direct policies regarding what information can be given out and under what circumstances

13 Securing the Physical Environment Take steps to secure the environment itself to reduce the risk of attacks: –Limiting the range of wireless data signals –Shielding wired signals –Controlling the environment –Suppressing the risk of fires

14 Limiting Wireless Signal Range Use the following techniques to limit the wireless signal range: –Relocate the access point –Substitute 80211a for 80211b –Add directional antenna –Reduce power –Cover the device –Modify the building

15 Shielding a Wired Signal The insulation and shielding that covers a copper cable does not always prevent a signal from leaking out or having an even stronger signal affect the data transmission on the cable This interference (noise) can be of several types Radio frequency interference (RFI) refers to interference caused by broadcast signals from a radio frequency (RF) transmitter, such as from a commercial radio or television transmitter

16 Shielding a Wired Signal (continued) Electromagnetic interference (EMI) may be caused by a variety of sources –A motor of another source of intense electrical activity can create an electromagnetic signal that interferes with a data signal –EMI can also be caused by cellular telephones, citizens’ band and police radios, small office or household appliances, fluorescent lights, or loose electrical connections

17 Shielding a Wired Signal (continued) The source of near end crosstalk (NEXT) interference is usually from another data signal being transmitted Loss of signal strength is known as attenuation Two types of defenses are commonly referenced for shielding a signal –Telecommunications Electronics Material Protected from Emanating Spurious Transmissions (TEMPEST) –Faraday cage

18 Shielding a Wired Signal (continued) TEMPEST –Classified standard developed by the US government to prevent attackers from picking up stray RFI and EMI signals from government buildings Faraday cage –Metallic enclosure that prevents the entry or escape of an electromagnetic field –Consists of a fine-mesh copper screening directly connected to an earth ground

19 Reducing the Risk of Fires In order for a fire to occur, four entities must be present at the same time: –Sufficient oxygen to sustain the combustion –Enough heat to raise the material to its ignition temperature –Some type of fuel or combustible material –A chemical reaction that is the fire itself

20 Reducing the Risk of Fires (continued) Refer to page 355 for the types of fires, their fuel source, how they can be extinguished, and the types of handheld fire extinguishers that should be used Stationary fire suppression systems that integrate into the building’s infrastructure and release a suppressant in the entire room are used

21 Reducing the Risk of Fires (continued) Systems can be classified as: –Water sprinkler systems that spray the room with pressurized water –Dry chemical systems that disperse a fine, dry powder over the fire –Clean agent systems that do not harm people, documents, or electrical equipment in the room

22 Understanding Business Continuity Process of assessing risks and developing a management strategy to ensure that business can continue if risks materialize Business continuity management is concerned with developing a business continuity plan (BCP) addressing how the organization can continue in the event that risks materialize

23 Understanding Business Continuity (continued) The basic steps in creating a BCP: –Understand the business –Formulate continuity strategies –Develop a response –Test the plan

24 Maintaining Utilities Disruption of utilities should be of primary concern for all organizations The primary utility that a BCP should address is electrical service An uninterruptible power supply (UPS) is an external device located between an outlet for electrical power and another device –Primary purpose is to continue to supply power if the electrical power fails

25 Maintaining Utilities (continued) A UPS can complete the following tasks: –Send a special message to the network administrator’s computer, or page or telephone the network manager to indicate that the power has failed –Notify all users that they must finish their work immediately and log off –Prevent any new users from logging on –Disconnect users and shut down the server

26 Establishing High Availability through Fault Tolerance The ability to endure failures (fault tolerance) can keep systems available to an organization Prevents a single problem from escalating into a total disaster Can best be achieved by maintaining redundancy Fault-tolerant server hard drives are based on a standard known as Redundant Array of Independent Drives (RAID)

27 Creating and Maintaining Backups Data backups are an essential element in any BCP Backup software can internally designate which files have already been backed up by setting an archive bit in the properties of the file Four basic types of backups: –Full backup –Differential backup –Incremental backup –Copy backup

28 Creating and Maintaining Backups (continued)

29 Creating and Maintaining Backups (continued) Develop a strategy for performing backups to make sure you are storing the data your organization needs A grandfather-father-son backup system divides backups into three sets: –A daily backup (son) –A weekly backup (father) –A monthly backup (grandfather)

30 Creating and Maintaining Backups (continued)

31 Planning for Disaster Recovery Business continuity is concerned with addressing anything that could affect the continuation of service Disaster recovery is more narrowly focused on recovering from major disasters that could cease operations for an extended period of time Preparing for disaster recovery always involves having a plan in place

32 Creating a Disaster Recovery Plan (DRP) A DRP is different from a business continuity plan Typically addresses what to do if a major catastrophe occurs that could cause the organization to cease functioning Should be a detailed document that is updated regularly All DRPs are different, but they should address the common features shown in the outline on pages 367 and 368 of the text

33 Identifying Secure Recovery Major disasters may require that the organization temporarily move to another location Three basic types of alternate sites are used during or directly after a disaster –Hot site –Cold site –Warm site

34 Identifying Secure Recovery (continued) A hot site is generally run by a commercial disaster recovery service that allows a business to continue computer and network operations to maintain business continuity A cold site provides office space but customer must provide and install all equipment needed to continue operations A warm site has all equipment installed but does not have active Internet or telecommunications facilities

35 Protecting Backups Data backups must be protected from theft and normal environmental elements Tape backups should be protected against strong magnetic fields, which can destroy a tape Be sure backup tapes are located in a secure environment that is adequately protected

36 Summary Adequate physical security is one of the first lines of defense against attacks Physical security involves restricting with access controls, minimizing social engineering attacks, and securing the environment and infrastructure Business continuity is the process of assessing risks and developing a management strategy to ensure that business can continue if risks materialize

37 Summary (continued) Disaster recovery is focused on recovering from major disasters that could potentially cause the organization to cease operations for an extended period of time A DRP typically addresses what to do if a major catastrophe occurs that could cause the organization to cease functioning