VII. Information flow is a useful mechanism that can enforce a variety of security policies that are hard to describe in simple access control lists. Describe how you can use information flow as a building block to catch the following attacks or vulnerabilities. Please specify the information sources and sinks that one should track $(1$ point $*3)$: $1.$ A buffer overflow attack that overwrites a function pointer. $2.$ Link following attack where a victim process reads a file from an attacker$-$controlled directory. $3.$ Skype app on Android accidentally stores the password in plaintext in a file that's accessible to everyone.