Which attack type involves sending a reset (RST) packet with an invalid checksum to confuse security appliances?

Which attack type involves sending a reset (RST) packet with an invalid checksum to confuse security appliances?

• A. Pre-Connection SYN
• B. invalid reset attack
• C. Fragmentation
• D. ASCII shellcodes

Answer: (B)

The main idea here is exploiting how TCP state is managed by security devices when a reset is involved. An RST packet is meant to immediately tear down a connection, and devices that perform stateful inspection rely on valid signals like correct checksums and proper sequencing to decide how to handle it. By sending a reset with an invalid checksum, an attacker tries to disrupt the security appliance’s interpretation of the TCP session. Some devices may mishandle or overlook the checksum issue, causing the appliance to reset or confuse its view of the connection, which can bypass or weaken enforcement and disrupt legitimate traffic. This targeted misuse of RST handling is what defines an invalid reset attack. The other options don’t fit this scenario because they describe different techniques: one is about initiating or spoofing connections before a session starts, another relies on breaking up traffic with fragmentation to evade detection, and the last involves injecting or disguising payloads with ASCII-encoded shellcodes.

The main idea here is exploiting how TCP state is managed by security devices when a reset is involved. An RST packet is meant to immediately tear down a connection, and devices that perform stateful inspection rely on valid signals like correct checksums and proper sequencing to decide how to handle it. By sending a reset with an invalid checksum, an attacker tries to disrupt the security appliance’s interpretation of the TCP session. Some devices may mishandle or overlook the checksum issue, causing the appliance to reset or confuse its view of the connection, which can bypass or weaken enforcement and disrupt legitimate traffic. This targeted misuse of RST handling is what defines an invalid reset attack.

The other options don’t fit this scenario because they describe different techniques: one is about initiating or spoofing connections before a session starts, another relies on breaking up traffic with fragmentation to evade detection, and the last involves injecting or disguising payloads with ASCII-encoded shellcodes.