TU Wien:Introduction to Security VU (Weippl)/Prüfung 2011-05-17 (Final Exam)

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Die zweite Prüfungsphase im SS2011 (Kapitel 10-18). In Klammer die Punkte.

Fragen[edit]

  • Describe the three basic services provided by a TPM. (3)
 authenticated boot: boot OS in stages and approve each for use. then can verify additional software. ==>resulting configuration well-defined with approved components
 certification: after authenticated boot. Can certify configuration to others. hierarchical certification approach (trust TPM->OS->applications)
 encryption: encrypts data for decryption by a certain machine in a given configuration. use master secret key to generate encryption key for possible configurations
  • Describe how a stack buffer overflow attack is implemented. (2)
 by overflowing local variables (which lay below the frame pointer and return address of a function) you could override those key elements with a desired address or directly with code
  • What is Address Space Randomisation, and why does it help against e.g stack overflows? (1)
 alter the location of data structures in the memory
  • What are the two broad categories of defences against buffer overflows? (1)
 run-time and compile-time defenses
  • What is input fuzzing and what are its benefits? Is it an automated or manual task? (2)
 usage of large random generated inputs to test correct behaviour of application. automated(?) and cheap
  • State the similarities and differences between command injection and SQL injection. (3)
  • List and describe measures for dealing with power loss. (1)
 Setting up uninterruptible power supply (UPS, may also be used as surge protector, power noise filter and automatic shutdown service),
 for longer blackouts other power sources such as a generator can be installed.
  • Define the security principles "separation of duties", "least privilege", "limited reliance on key employees". (2)
 separation of duties: Separation of duty requires that for particular sets of transactions, no single individual be allowed to execute all transactions within the set. 
   The most commonly used examples are the separate transactions needed to initiate a payment and to authorize a payment
 least privilge: requires that a user be given no more privilege than necessary to perform a job
 limited reliance on key employees: (?) somehow self-explanatory...
  • What is the ss-property in the BLP? What are the other two properties? (3)
 simple security - "no read up" You are only allowed to read Object which security classification level is lower than yours (Si, Oj, read) has fc(Si) ≥ fo(Oj).
 other two: *-property ("no write down"), ds-property
  • Define the terms: Asset, Threat, Vulnerability, Risk, and their relationship. (3)
 Asset: Anything that has value to the organization
 Threat: A potential cause of an unwanted incident which may result in harm
 Vulnerability: A weakness in an asset or group of assets which can be exploited by a threat.
 Risk: The potential that a given threat will exploit vulnerabilities
  • List and briefly define the 4 steps in the iterative security management process. (2)
 Plan, Do, Check, Act
  • What are the benefits of developing an incident response capability? (2)