How effectivness of validating tehcnique Streemsex
Say you want to set up a site where users can upload arbitrary files so they can share them or download them again from another location.
In this case validation is impossible because there is no valid or invalid content.
However, there are bad, good and "best" approaches.
Often the best approach is the simplest in terms of code.
Here are some examples: If you expect a phone number, you can strip out all non-digit characters.
Thus, "(555)123-1234", "555.123.1234", and "555\"; DROP TABLE USER;--123.1234" all convert to 5551231234.
Some documentation and references interchangeably use the various meanings, which is very confusing to all concerned.
This confusion directly causes continuing financial loss to the organization.
This strategy is directly akin to anti-virus pattern updates.To ensure that the application is robust against all forms of input data, whether obtained from the user, infrastructure, external entities or database systems. This weakness leads to almost all of the major vulnerabilities in applications, such as Interpreter Injection, locale/Unicode attacks, file system attacks and buffer overflows. All sections should be reviewed The most common web application security weakness is the failure to properly validate input from the client or environment.Unless the business will allow updating "bad" regexes on a daily basis and support someone to research new attacks regularly, this approach will be obviated before long.Rather than accept or reject input, another option is to change the user input into an acceptable format Any characters which are not part of an approved list can be removed, encoded or replaced.
Otherwise, you are allowing attackers to repeatedly attack your application until they find a vulnerability that you haven't protected against.