The book that we use is Computer Security Art and Science by Matt Bishop. Each answer should be from 600- 900 words.

Answer the following questions.

1)(12 pts.) Chapter 18 (pgs. 494-495) -Problem#7

A company develops a new security product using the extreme programming software development methodology. Programmers code, then test, then add more code, then test, and continue this iteration. Every day, they test the code base as a whole. The programmers work in pairs when writing code to ensure that al least two people review the code. The company does not adduce any additional evidence of assurance. How would explain to the management of this company why their software is in fact not "High-assurance" software?

2) (15 pts.) Chapter 22 (pgs. 642-643) -Problem#2

Consider how a system with capabilities as its access control mechanism could deal with Trojan horses.

1. In general, do capabilities offer more or less protection against Trojan horses than do access control lists? Justify you answer in light of the theoretical equivalence of ACLs and C-Lists.
2. Consider now the inheritance properties of new processes. If the creator controls which capabilities the created process is given initially, how could the creator limit the damage that a Trojan horse could do?
3. Can capabilities protect against all Trojan horses? Either show that they can or describe a Trojan horse process that C-Lists cannot protect against.

3) (18 pts.) Chapter 22 (pgs. 642-643) -Problem#12

Assume that the Clark- Wilson model is implemented on a computer system. Could a computer virus that scrambled constrained data items be introduced into the system? Why or why not? Specifically, if not, identify the precise control that would prevent the virus from being introduced, and explain why it would prevent the virus from being introduced; if yes, identify the specific control or controls that would allow the virus to be introduced and explain why they fail to keep it out.

4) (20 pts.) Chapter 23 (pgs. 685-687) -Problem#1

Classify the following vulnerabilities using the RISOS model. Assume that the classification is for the implementation level. Justify your answer.

1. The presence of the "wiz" command in the sendmail program (see Section 23.2.8)
2. The failure to handle the IFS shel variable by loadmodule. (see Section 23.2.8).
3. The failure to select an Administrator password that was difficult to guess. (see Section 23.2.9).
4. The failure of the Burroughs system to detect offline changes to files (see Section 23.2.6).

5) (15 pts.) Chapter 23 (pgs. 685-687) -Problem#4

A common error on UNIX systems occurs during the configuration of bind, and directory name server. The time-to-expire field is set at 0.5 because the administrator believes that this fields unit is minutes (and wishes to set the time to 30 seconds). However, bind expects the field to be in seconds and reads the value as 0- meaning that no data is ever expired.

1. Classify this vulnerability using the RISOS model, and justify your answer
2. Classify this vulnerability using the PA model, and justify your answer.
3. Classify this vulnerability using Aslam's model, and justify your answer,