GIAC GSNA Exam With Confidence Using Practice Dumps

In DNS poisoning attack, an attacker distributes incorrect IP address. DNS cache poisoning is a maliciously created or unintended situation that provides data to a caching name server that did not originate from authoritative Domain Name System (DNS) sources. Once a DNS server has received such non-authentic datA, Caches it for future performance increase, it is considered poisoned, supplying the non-authentic data to the clients of the server. To perform a cache poisoning attack, the attacker exploits a flaw in the DNS software. If the server does not correctly validate DNS responses to ensure that they are from an authoritative source, the server will end up caching the incorrect entries locally and serve them to other users that make the same request. Answer: B is incorrect. IP (Internet Protocol) address spoofing is an attack in which an attacker creates the IP packets with a forged (spoofed) source IP address with the purpose of concealing the identity of the sender or impersonating another computing system. The basic protocol for sending data over the Internet and many other computer networks is the Internet Protocol ("IP"). The header of each IP packet contains, among other things, the numerical source and destination address of the packet. The source address is normally the address that the packet was sent from. By forging the header so it contains a different address, an attacker can make it appear that the packet was sent by a different machine. The machine that receives spoofed packets will send response back to the forged source address, which means that this technique is mainly used when the attacker does not care about the response or the attacker has some way of guessing the response. Answer: D is incorrect. Man-in-the-middle attacks occur when an attacker successfully inserts an intermediary software or program between two communicating hosts. The intermediary software or program allows attackers to listen to and modify the communication packets passing between the two hosts. The software intercepts the communication packets and then sends the information to the receiving host. The receiving host responds to the software, presuming it to be the legitimate client. Answer: C is incorrect. MAC flooding is a technique employed to compromise the security of network switches. In a typical MAC flooding attack, a switch is flooded with packets, each containing different source MAC addresses. The intention is to consume the limited memory set aside in the switch to store the MAC address-to-physical port translation table. The result of this attack causes the switch to enter a state called failopen mode, in which all incoming packets are broadcast out on all ports (as with a hub), instead of just down the correct port as per normal operation. A malicious user could then use a packet sniffer (such as Wireshark) running in promiscuous mode to capture sensitive data from other computers (such as unencrypted passwords, e-mail and instant messaging conversations), which would not be accessible were the switch operating normally.