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.

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 – These system need 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.

The following reference(s) were/was used to create this question:

CISA review manual 2014 Page number 346 and 347