312-50 Exam - Ethical Hacking and Countermeasures (CEHv6)

certleader.com

Q1. What is the proper response for a NULL scan if the port is closed? 

A. SYN 

B. ACK 

C. FIN 

D. PSH 

E. RST 

F. No response 

Answer:

Explanation: Closed ports respond to a NULL scan with a reset. 

Q2. Which of the following snort rules look for FTP root login attempts? 

A. alert tcp -> any port 21 (msg:"user root";) 

B. alert tcp -> any port 21 (message:"user root";) 

C. alert ftp -> ftp (content:"user password root";) 

D. alert tcp any any -> any any 21 (content:"user root";) 

Answer: D

Explanation: The snort rule header is built by defining action (alert), protocol (tcp), from IP subnet port (any any), to IP subnet port (any any 21), Payload Detection Rule Options (content:”user root”;) 

Q3. Jim’s organization has just completed a major Linux roll out and now all of the organization’s systems are running the Linux 2.5 kernel. The roll out expenses has posed constraints on purchasing other essential security equipment and software. The organization requires an option to control network traffic and also perform stateful inspection of traffic going into and out of the DMZ. 

Which built-in functionality of Linux can achieve this? 

A. IP Tables 

B. IP Chains 

C. IP Sniffer 

D. IP ICMP 

Answer: A

Explanation: iptables is a user space application program that allows a system administrator to configure the netfilter tables, chains, and rules (described above). Because iptables requires elevated privileges to operate, it must be executed by user root, otherwise it fails to function. On most Linux systems, iptables is installed as /sbin/iptables. IP Tables performs stateful inspection while the older IP Chains only performs stateless inspection. 

Q4. Justine is the systems administrator for her company, an international shipping company with offices all over the world. Recent US regulations have forced the company to implement stronger and more secure means of communication. Justine and other administrators have been put in charge of securing the company's digital communication lines. After implementing email encryption, Justine now needs to implement robust digital signatures to ensure data authenticity and reliability. Justine has decided to implement digital signatures which are a variant of DSA and that operate on elliptical curve groups. These signatures are more efficient than DSA and are not vulnerable to a number field sieve attacks. 

What type of signature has Justine decided to implement? 

A. She has decided to implement ElGamal signatures since they offer more reliability than the typical DSA signatures 

B. Justine has decided to use ECDSA signatures since they are more efficient than DSA signatures 

C. Justine is now utilizing SHA-1 with RSA signatures to help ensure data reliability 

D. These types of signatures that Justine has decided to use are called RSA-PSS signatures 

Answer: B

Explanation: The Elliptic Curve Digital Signature Algorithm (ECDSA) is a variant of the Digital Signature Algorithm (DSA) which uses Elliptic curve cryptography. http://en.wikipedia.org/wiki/Elliptic_Curve_DSA 

Q5. Liza has forgotten her password to an online bookstore. The web application asks her to key in her email so that they can send her the password. Liza enters her email liza@yahoo.com'. The application displays server error. What is wrong with the web application? 

A. The email is not valid 

B. User input is not sanitized 

C. The web server may be down 

D. The ISP connection is not reliable 

Answer: B

Explanation: All input from web browsers, such as user data from HTML forms and cookies, must be stripped of special characters and HTML tags as described in the following CERT advisories: http://www.cert.org/advisories/CA-1997-25.html http://www.cert.org/advisories/CA-2000-02.html 

Q6. Sara is making use of Digest Authentication for her Web site. Why is this considered to be more secure than Basic authentication? 

A. Basic authentication is broken 

B. The password is never sent in clear text over the network 

C. The password sent in clear text over the network is never reused. 

D. It is based on Kerberos authentication protocol 

Answer: B

Explanation: Digest access authentication is one of the agreed methods a web page can use to negotiate credentials with a web user (using the HTTP protocol). This method builds upon (and obsoletes) the basic authentication scheme, allowing user identity to be established without having to send a password in plaintext over the network. 

Q7. In the context of Trojans, what is the definition of a Wrapper? 

A. An encryption tool to protect the Trojan. 

B. A tool used to bind the Trojan with legitimate file. 

C. A tool used to encapsulated packets within a new header and footer. 

D. A tool used to calculate bandwidth and CPU cycles wasted by the Trojan. 

Answer: B

Explanation: These wrappers allow an attacker to take any executable back-door program and combine it with any legitimate executable, creating a Trojan horse without writing a single line of new code. 

Q8. LAN Manager passwords are concatenated to 14 bytes and split in half. The two halves are hashed individually. If the password is 7 characters or less, than the second half of the hash is always: 

A. 0xAAD3B435B51404EE 

B. 0xAAD3B435B51404AA 

C. 0xAAD3B435B51404BB 

D. 0xAAD3B435B51404CC 

Answer: A

Explanation: A problem with LM stems from the total lack of salting or cipher block chaining in the hashing process. To hash a password the first 7 bytes of it are transformed into an 8 byte odd parity DES key. This key is used to encrypt the 8 byte string "KGS!@". Same thing happens with the second part of the password. This lack of salting creates two interesting consequences. Obviously this means the password is always stored in the same way, and just begs for a typical lookup table attack. The other consequence is that it is easy to tell if a password is bigger than 7 bytes in size. If not, the last 7 bytes will all be null and will result in a constant DES hash of 0xAAD3B435B51404EE. 

Q9. Let's imagine three companies (A, B and C), all competing in a challenging global environment. Company A and B are working together in developing a product that will generate a major competitive advantage for them. Company A has a secure DNS server while company B has a DNS server vulnerable to spoofing. With a spoofing attack on the DNS server of company B, company C gains access to outgoing e-mails from company B. How do you prevent DNS spoofing? (Select the Best Answer.) 

A. Install DNS logger and track vulnerable packets 

B. Disable DNS timeouts 

C. Install DNS Anti-spoofing 

D. Disable DNS Zone Transfer 

Answer: C

Explanation: Explantion: Implement DNS Anit-Spoofing measures to prevent DNS Cache Pollution to occur. 

Q10. John has performed a scan of the web server with NMAP but did not gather enough information to accurately identify which operating system is running on the remote host. How could you use a web server to help in identifying the OS that is being used? 

A. Telnet to an Open port and grab the banner 

B. Connect to the web server with an FTP client 

C. Connect to the web server with a browser and look at the web page 

D. Telnet to port 8080 on the web server and look at the default page code 

Answer:

Explanation: Most Web servers politely identify themselves and the OS to anyone who asks.