CEH v13 Changed 312-50v13 Questions

The Certified Ethical Hacker (CEH) Cryptography module explains that one of the primary challenges in encryption is secure key distribution. Asymmetric encryption, also known as public-key cryptography, was specifically designed to address this issue.

In asymmetric encryption, each entity possesses a public key and a private key. The public key can be shared openly, allowing anyone to encrypt data securely, while only the corresponding private key can decrypt it. CEH documentation highlights that this model eliminates the need to transmit secret keys over insecure channels.

Option D is correct because asymmetric encryption enables secure key exchange without prior trust.

Option B (symmetric encryption) requires a shared secret key and suffers from key distribution challenges.

Option A refers to data-at-rest protection, not key exchange.

Option C provides integrity verification, not encryption.

CEH emphasizes that asymmetric encryption underpins secure protocols such as TLS and digital certificates.

A SYN flood attack is a type of denial-of-service (DoS) attack that exploits the TCP handshake process by sending a large number of SYN requests to the target server, without completing the connection. This consumes the connection state tables on the server, preventing it from accepting new connections. The attacker has crafted an automated botnet to simultaneously send ‘s’ SYN packets per second to the server. The server can handle ‘f’ SYN packets per second without any performance issues. If ‘s’ exceeds ‘f’, the network infrastructure begins to show signs of overload. The system’s response time increases exponentially (24k), where ‘k’ represents each additional SYN packet above the ‘f’ limit.

Considering ‘s=500’ and different ‘f’ values, the scenario that is most likely to cause the server to experience overload and significantly increased response times is the one where ‘f=420’. This is because ‘s’ is greater than ‘f’ by 80 packets per second, which means the server cannot handle the incoming traffic and will eventually run out of resources. The response time shoots up (2480 = 281,474,976,710,656 times the normal response time), indicating a system overload.

The other scenarios are less likely or less severe than the one where ‘f=420’. Option A has ‘f=510’, which is greater than ‘s’, so the system stays stable and the response time remains unaffected. Option B has ‘f=495’, which is less than ‘s’ by 5 packets per second, so the response time drastically rises (245 = 32 times the normal response time), indicating a probable system overload, but not as extreme as option D. Option C has ‘f=505’, which is less than ‘s’ by 5 packets per second, so the response time increases but not as drastically (245 = 32 times the normal response time), and the system might still function, albeit slowly. References:

SYN flood DDoS attack | Cloudflare

SYN flood - Wikipedia

What Is a SYN Flood Attack? | F5

What is a SYN flood attack and how to prevent it? | NETSCOUT

CEH training emphasizes that mobile applications frequently mishandle local storage, leaving sensitive data such as tokens, passwords, API keys, or personal information unencrypted within SQLite databases, shared preferences, or flat-file storage. When encryption is absent or improperly implemented, attackers can directly access this data through filesystem extraction, Android Debug Bridge (ADB) access, physical device access, or rooted environments. CEH identifies “Insecure Data Storage” as one of the most critical mobile vulnerabilities because it bypasses server-side defenses entirely. Since the vulnerability specifically concerns data at rest, the most direct and effective exploitation method is to retrieve the locally stored unencrypted data. SQL injection (Option B) evaluates backend security, not device storage. XSS (Option C) is a web attack and unrelated to local encryption. Brute-forcing credentials (Option D) is unnecessary when sensitive information is already stored insecurely. Therefore, accessing local storage is the correct exploitation method.

Zone transfers (AXFR) are DNS operations used to replicate DNS data from a primary to a secondary server. If improperly configured, attackers can request these transfers and retrieve valuable DNS information, including hostnames and IPs.

Correct Statements:

A: Zone transfers are DNS protocol operations.

C: They transfer the entire DNS zone file (records for the domain).

E: Zone transfers use TCP port 53. Blocking it can prevent unauthorized transfers.

From CEH v13 Courseware:

Module 3: Scanning Networks

Topic: DNS Enumeration → Zone Transfers

CEH v13 Study Guide states:

“A zone transfer is a mechanism used by DNS servers to replicate databases. It can be used by attackers to retrieve detailed DNS information if not properly restricted. Zone transfers occur over TCP port 53.”

Incorrect Statements:

B/D: nslookup is a query tool; it doesn’t perform or manage zone transfers.

F: Zone transfers can happen on the internet if DNS servers are misconfigured.