# T1 **Deadline:** Wednesday, September 12, 2018, 11:55 pm *This assignment should be completed individually* ## Problem 1 Consider the following web-based email system. Users login by visiting a pre-specified URL for the system and then entering both an identifier (i.e., a username) and a password. This starts a session that is associated with the specified identity. The system then displays in a preview frame a list of messages that have been sent to that identity and have not been deleted during this or some prior session associated with that identity. Here, for each message, the name of the sender and the contents of the message are displayed. During a session, a user can: 1. Click on an icon to generate a reply to the message the user is currently viewing. The user then types the body of the reply. That reply later becomes a message that will be available for viewing by the sender of the original message to which this serves as a reply. 2. Click on an icon to generate a new message. The user then enters an identity of some receiver and enters a body for the message. That body is incorporated into a message that will be available for later viewing by the intended receiver. 3. Click on an icon to delete the message that the user is currently viewing. 4. Click on an icon to end the session. However, if 15 minutes elapses during which no action is taken by the user, then the system automatically terminates the session. **Threat model:** The adversary is a user who desires to read email, generate bogus email, and/or alter email that has been generated by bona fide users. The adversary has access to the URL for the mail system and also can read, delete, and/or update network packets in transit. The adversary cannot physically access or run programs on a user’s machine that is running a browser to access the mail system. And the adversary cannot physically access or run programs on the mail system server. **To Do:** Identify a list of security policies for this system. Try to be comprehensive, but don’t go over one page. For each security policy, label with one of: confidentiality, integrity, or availability. ## Problem 2 The <a href="https://www.pomona.edu/administration/its/policies/appropriate-use-policy">Claremont Colleges Policy Regarding Appropriate Use of Campus Computing and Network Resources</a> is, in part, a security policy that stipulates appropriate usage of computer systems at the Claremont Colleges. As a student studying computer security, you obviously need to know your responsibilities with respect to that policy. And as a security expert, you might some day be asked to write such a security policy or to evaluate somebody’s actions relative to a policy. So study the policy, then consider the following problem. Suppose that a CS 181S student discovers a vulnerability that can be exploited to bypass the usual authentication used to login to Claremont Colleges systems. Such exploitation would enable an attacker to login under any userID of their choice, thus impersonating any member of the community. The attack would yield access to all email, student grades, and student financial statements. **To Do:** Discuss whether each of the following behaviors is permitted by the Claremont Colleges Policy linked above: 1. The student programs a tool that accomplishes the attack. The student uses the tool, but only to read files they are already allowed to access with their userID. 2. The student programs a tool that accomplishes the attack. The student doesn’t actually use the tool but posts it to a well-known website, along with instructions for use of the tool. 3. The student does not program an attack tool but does post a discussion of how the attack would work to the “Overheard Claremont Colleges” Facebook page (i.e., a well-known public website). The discussion contains sufficient technical details to enable a CS major to program an attack tool. Explain your reasoning. You will be evaluated in part on how well-supported your arguments are, but do not go over one page. It is to your advantage to quote specific excerpts from the policy that support your arguments. ## Feedback This is the first time this course has been offered. In the interest of improving future iterations of this course, please answer the following questions: 1. How long did you spend on this assignment? 2. Any comments or feedback? Things you found interesting? Things you found challenging? Things you found boring? ### Collaboration Policy Each student should submit their own solution to this assignment. You may discuss ideas with other students at a high-level, but under no circumstances should you be looking at another student’s solution. Any ideas that originated with another person should be cited. ### What to Submit Submit your solution as a 3-page pdf on Sakai. Use 10 point or larger font. Start each problem’s solution on a new page. Use at most 1 page per problem. (Use the third page to answer the feedback questions.) Submissions that fail to follow the submission guidelines may be subject to a 10% deduction.