Autocomplete is Enabled

Summary

Netsparker detected that Autocomplete is Enabled in one or more of the form fields which might contain sensitive information like "username", "credit card" or "CVV".

Impact

If user chooses to save, data entered in these fields will be cached by the browser. An attacker who can access the victim's browser could steal this information. This is especially important if the application is commonly used in shared computers, such as cyber cafes or airport terminals.

Actions To Take

Add the attribute autocomplete="off" to the form tag or to individual "input" fields. However, since early 2014, major browsers don't respect this instruction, due to their integrated password management mechanism, and offer to users to store password internally.
Find all instances of inputs that store private data and disable autocomplete. Fields which contain data such as "Credit Card" or "CCV" type data should not be cached. You can allow the application to cache usernames and remember passwords; however, in most cases this is not recommended.
Re-scan the application after addressing the identified issues to ensure all of the fixes have been applied properly.

Required Skills for Successful Exploitation

First and foremost, attacker needs either physical access or user-level code execution rights for successful exploitation. Dumping all data from a browser can be fairly easy, and a number of automated tools exist to undertake this. Where the attacker cannot dump the data, he/she could still browse the recently visited websites and activate the autocomplete feature to see previously entered values.

Classifications

WASC-15, OWASP 2013-A5, OWASP 2017-A6