Chapter 10: Operational Security

1
Chapter 10 Operational Security

• Security Guide to Network Security Fundamentals
• Second Edition

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

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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

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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

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Controlling Access with Physical Barriers
(continued)
7
Controlling Access with Physical Barriers
(continued)
8
Controlling Access with Physical Barriers
(continued)

• 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)

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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

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Controlling Access with Biometrics

• Biometrics uses a persons 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)

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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

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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

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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

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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

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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

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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

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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

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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 buildings infrastructure and
  release a suppressant in the entire room are used

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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

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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

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Understanding Business Continuity (continued)

• The basic steps in creating a BCP
• Understand the business
• Formulate continuity strategies
• Develop a response
• Test the plan

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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

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Maintaining Utilities (continued)

• A UPS can complete the following tasks
• Send a special message to the network
  administrators 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

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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)

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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

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Creating and Maintaining Backups (continued)
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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)

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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

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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

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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

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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

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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

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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