The Nelm Company has discovered through experience that somehow Erm, its major competitor, seems to discover its every secret. For example, when Nelm launches a new advertising campaign, Erm always immediately launches an advertising campaign that appears to be specifically designed to nullify the effects of Nelm’s advertisements. Barbara Woods, the head of Nelm’s security department, is convinced that somehow Erm is invading its computer network and browsing secret files at will. Nelm’s network is set up as follows:
a. One large Web server machine that also supports applications for 15 users in the sales department.
b. The Web server is on a local area network, and the files for the 15 users in the sales department are shared with users in engineering and production.
c. Nelm supports Internet- based e- mail services for all its employees.

Required
a. Describe security flaws in Nelm’s system.
b. Make suggestions for improving Nelm’s security system. How might Erm be invading Nelm’s network?