CISA Certified Information Systems Auditor – Question2156

There are many known weaknesses within an Intrusion Detection System (IDS). Which of the following is NOT a limitation of an IDS?

A.
Weakness in the identification and authentication scheme.
B. Application level vulnerability.
C. Backdoor into application
D. Detect zero day attack.

Correct Answer: D

Explanation:

Explanation:
Detecting zero day attack is an advantage of IDS system making use of behavior or heuristic detection.
It is important to read carefully the question. The word “NOT” was the key word.
Intrusion Detection System are somewhat limited in scope, they do not address the following:
Weakness in the policy definition
Application-level vulnerability
Backdoor within application
Weakness in identification and authentication schemes
Also, you should know the information below for your CISA exam:
An IDS works in conjunction with routers and firewall by monitoring network usage anomalies.
Broad category of IDS includes:
1. Network Based IDS
2. Host Based IDS
Network Based IDS
They identify attack within the monitored network and issue a warning to the operator.
If a network based IDS is placed between the Internet and the firewall, it will detect all the attack attempts whether or not they enter the firewall
Network Based IDS are blinded when dealing with encrypted traffic
Host Based IDS
They are configured for a specific environment and will monitor various internal resources of the operating system to warn of a possible attack.
They can detect the modification of executable programs, detect the detection of files and issue a warning when an attempt is made to use a privilege account.
They can monitor traffic after it is decrypted and they supplement the Network Based IDS.
Types of IDS includes:
Statistical Based IDS – This system needs a comprehensive definition of the known and expected behavior of system
Neural Network – An IDS with this feature monitors the general patterns of activity and traffic on the network, and create a database. This is similar to statistical model but with added self-learning functionality.
Signature Based IDS – These IDS system protect against detected intrusion patterns. The intrusive pattern they can identify are stored in the form of signature.
The following were incorrect answers:
The other options mentioned are all limitations of an IDS.
Reference:
CISA review manual 2014 Page number 346 and 347