Get The SecOps Group CNSP Exam Practice Questions - Real and Updated

Answer : A

Symmetric encryption is a cryptographic technique where the same key is used for both encryption and decryption processes. In the context of network security, when data is encrypted prior to transmission and decrypted at the receiving end using a symmetric encryption algorithm (e.g., AES or Triple-DES), both the sender and receiver must share and utilize an identical secret key. This key is applied by the sender to transform plaintext into ciphertext and by the receiver to reverse the process, recovering the original plaintext. The efficiency of symmetric encryption makes it ideal for securing large volumes of data transmitted over networks, provided the key is securely distributed and managed.

Why A is correct: Option A accurately describes the fundamental property of symmetric encryption---using a single shared key for both encryption and decryption. This aligns with CNSP documentation, which emphasizes symmetric encryption's role in securing data in transit (e.g., via VPNs or secure file transfers).

Why other options are incorrect:

B: This describes asymmetric encryption (e.g., RSA), where different keys (public and private) are used for encryption and decryption, not symmetric encryption.

C: Symmetric encryption inherently relies on keys; the absence of keys contradicts its definition and operational mechanism.

D: Symmetric encryption is not inherently insecure; its security depends on key strength and management practices, not the algorithm itself. CNSP highlights that algorithms like AES are widely regarded as secure when implemented correctly.

Answer : D

ICMP (Internet Control Message Protocol), per RFC 792, handles diagnostics (e.g., ping) and errors in IP networks. It's exploitable in:

A . Ping of Death:

Method: Sends oversized ICMP Echo Request packets (>65,535 bytes) via fragmentation. Reassembly overflows buffers, crashing older systems (e.g., Windows 95).

Fix: Modern OSes cap packet size (e.g., ping -s 65500).

B . Smurf Attack:

Method: Spoofs ICMP Echo Requests to a network's broadcast address (e.g., 192.168.255.255). All hosts reply, flooding the victim.

Amplification: 100 hosts = 100x traffic.

C . ICMP Flooding:

Method: Overwhelms a target with ICMP Echo Requests (e.g., ping -f), consuming bandwidth/CPU.

Variant: BlackNurse attack targets firewalls.

Technical Details:

ICMP Type 8 (Echo Request), Type 0 (Echo Reply) are key.

Mitigation: Rate-limit ICMP, disable broadcasts (e.g., no ip directed-broadcast).

Security Implications: ICMP attacks are DoS vectors. CNSP likely teaches filtering (e.g., iptables -p icmp -j DROP) balanced with diagnostics need.

Why other options are incorrect:

A, B, C individually: All are ICMP-based; D is comprehensive.

Real-World Context: Smurf attacks peaked in the 1990s; modern routers block them by default.

Answer : A

The EICAR test file is a standardized tool in security testing, designed for a specific purpose.

Why A is correct: The EICAR file (a 68-byte string) triggers antivirus detection without harm, testing response capabilities. CNSP recommends it for AV validation.

Why B is incorrect: It has no role in testing encryption; it's solely for AV functionality.

Answer : A

A DNS zone transfer involves replicating the DNS zone data (e.g., all records for a domain) from a primary to a secondary DNS server, requiring a reliable transport mechanism.

Why A is correct: DNS zone transfers use TCP port 53 because TCP ensures reliable, ordered delivery of data, which is critical for transferring large zone files. CNSP notes that TCP is the standard protocol for zone transfers (e.g., AXFR requests), as specified in RFC 5936.

Why other options are incorrect:

B . 53/UDP: UDP port 53 is used for standard DNS queries and responses due to its speed and lower overhead, but it is not suitable for zone transfers, which require reliability over speed.

C . Both 1 and 2: This is incorrect because zone transfers are exclusively TCP-based, not UDP-based.

D . None of the above: Incorrect, as 53/TCP is the correct port for DNS zone transfers.

Answer : A

DNS cache poisoning, also known as DNS spoofing, involves an attacker injecting false DNS records into a resolver's cache, altering how domain names resolve.

Why A is correct: The primary risk is that an attacker can redirect users to malicious websites (e.g., phishing or malware sites) by poisoning the DNS cache with fake IP addresses. This can lead to credential theft, data exfiltration, or malware distribution. CNSP identifies this as the core threat of DNS cache poisoning, aligning with real-world attack vectors.

Why other option is incorrect:

B . Manipulate the cache of the web server or proxy server: This describes web cache poisoning, a different attack targeting HTTP caches, not DNS servers. DNS cache poisoning affects DNS resolution, not web or proxy server caches directly.