Why is “Black List” input validation considered a weak validation method ?
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Because the validation settings are hard coded.
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Susceptible to bypass using various forms of character encoding
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Because it's difficult to implement a black list filter that also takes into account data sent using the POST method
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Because it is typically implemented using regular expressions to match known good data patterns
Black list validation is weak because attackers can bypass filters using character encoding variations like URL encoding, Unicode, or hex encoding. White list validation is more secure because it only allows known-good patterns. Hard coding (A) and POST method handling (C) aren't fundamental weaknesses, and black lists don't use regex patterns (D).
To answer this question, you need to understand the concept of "Black List" input validation and its weaknesses.
Option A) Because the validation settings are hard coded - This option is incorrect because the weakness of "Black List" input validation does not depend on whether the validation settings are hard coded or not.
Option B) Susceptible to bypass using various forms of character encoding - This option is correct. "Black List" input validation involves creating a list of known malicious inputs and rejecting any input that matches those patterns. However, attackers can bypass this method by using various forms of character encoding to disguise their malicious inputs. Therefore, it is considered a weak validation method.
Option C) Because it's difficult to implement a black list filter that also takes into account data sent using the POST method - This option is incorrect. The weakness of "Black List" input validation is not related to the difficulty of implementing a black list filter for data sent using the POST method.
Option D) Because it is typically implemented using regular expressions to match known good data patterns - This option is incorrect. While regular expressions may be used to implement "Black List" input validation, it is not the reason why it is considered a weak validation method.
The correct answer is B) Susceptible to bypass using various forms of character encoding. This option is correct because attackers can exploit the weaknesses of "Black List" input validation by using different character encoding techniques to evade detection.