Answer and Explanation:
Network security risks if an attacker is able to break such a pseudo-random number generator (PRNG) so that ith number generated can be easily computed by (i-1)st number generated are as follows :
1. Session hijack: If the attacker has previously generated PRNG code, he will easily generate the current session sequence number random code to hijack the current session.
2. Counterfeit packets: With help of previously PRNG generated sequence number next sequence numbers are also predicted, which leads to counterfeit packets.
3. Code Injection: By predicting sequence numbers attacker can inject malicious code in the TCP segments.
4. Denial of service attack: This attack is caused by bot nets, when bot nets have legitimate access to a TCP segment. The bot nets will perform distributed denial of service attack.
5. Premature closure of an existing TCP connection: this kind of premature closure is performed by setting RST bit.