Calvin, a grey-hat hacker, targets a web application that has design flaws in its authentication mechanism. He enumerates usernames from the login form of the web application, which requests users to feed data and specifies the incorrect field in case of invalid credentials. Later, Calvin uses this information to perform social engineering.
Which of the following design flaws in the authentication mechanism is exploited by Calvin?
Calvin is exploiting verbose failure messages in the web application's authentication mechanism. Verbose failure messages occur when the application specifies which field (username or password) is incorrect during a failed login attempt. This allows attackers to enumerate valid usernames by testing different combinations, as the application informs them if the username or the password is invalid. This information is later used for social engineering attacks. Verbose failure messages provide attackers with a clear indication of which part of their input was incorrect, making it easier to identify and exploit valid usernames.
D. Verbose failure messages p1848 Username Enumeration Attackers can enumerate usernames in two ways: verbose failure messages and predictable usernames. o Verbose Failure Message In a typical login system, the user enters two fields, namely username and password. In some cases, an application will ask for additional information. If the user is trying to log in and fails, it implies that at least one field was incorrect. This provides grounds for an attacker to exploit the application. Examples: Account <username> not found Incorrect password provided Account <username> has been locked out
The correct answer is D. Verbose failure messages as per the CEH book, Module 14 Page 1848, If the user is trying to log in and fails, it implies that at least one field was incorrect. This provides grounds for an attacker to exploit the application. Password reset mechanism is a password cracking tool, hence why I believe 'D' is the correct answer to this question.
Most authentication mechanisms used by web applications have design flaws. Attackers can identify these flaws and exploit them to gain unauthorized access to the web application. Such design flaws include failure to check password strength, insecure transmission of credentials over the Internet, etc. Web applications usually authenticate their clients or users by a combination of a username and password, which can be identified and exploited. Username Enumeration Attackers can enumerate usernames in two ways: verbose failure messages and predictable usernames. o Verbose Failure Message In a typical login system, the user enters two fields, namely username and password. In some cases, an application will ask for additional information. If the user is trying to log in and fails, it implies that at least one field was incorrect. This provides grounds for an attacker to exploit the application.
VERBOSE FAILURE MESSAGES: ANY LOGIN FORM OF AN APPLICATION REQUESTS USERS TO FEED AT LEAST TWO FIELDS, NAMELY USERNAME AND PASSWORD. A FEW APPLICATIONS MAY ALSO ASK FOR ADDITIONAL PARAMETERS SUCH AS DOB, ANSWER TO A SECURITY QUESTION, AND OTP PIN, TO VALIDATE A USER. IF THE LOGIN ATTEMPT IS UNSUCCESSFUL, THE APPLICATION INDICATES THAT THE INFORMATION PROVIDED IS NOT VALID. >>>>>>>>>>WHEN THE APPLICATION SPECIFIES WHICH FIELD IS INCORRECT OR POPS UP REASONS FOR DENYING ACCESS, ATTACKERS CAN EASILY EXPLOIT THAT FIELD BY TRYING A LARGE SET OF SIMILAR NAMES OR WORDS TO ENUMERATE VALID DATA REQUIRED TO ACCESS THE APPLICATION. >>>>>>THE LIST OF ENUMERATED DATA CAN ALSO BE USED LATER FOR SOCIAL ENGINEERING
Attack Authentication Mechanism - Username Enumeration Exploit design and implementation flaws in web applications, such as failure to check password strength or insecure transmission of credentials, to bypass authentication mechanisms. verbose failure messages - In a typical login system, the user enters two fields, namely username and password. In some cases, an application will ask for additional information. (P.1864/1848)
D. Is the correct answer.
The correct option is D. Verbose failure messages
in my opinion the correct answer is D) Verbose failure messages
is D. Verbose failure messages
The answer is D
D is correct answer
verbose error
The mechanism is the password reset. "Generating the verbose error, specifying if the username is valid" from the CEH book p1867 Verbose failure message is the way he get information.
A - I think password reset mechanism
Verbose failure messages
Verbose failure messages. Password reset mechanism is neutral and required for the whole auth mngt cycle, not a flaw.
D. Verbose failure messages