💖Input Validation Errors: Improper Incorporation of Malicious Inputs into Format Strings

• In Java, format strings implementation is stricter than in any other languages
• If any conversion argument fails to match with the corresponding format specifier, implementation method throws an exception
• This method aims at limiting malicious exploits; although a malicious user input can yet exploit format strings and cause denial of service or data leaks
• It is advisable to not incorporate any input strings of untrusted sources into format strings

Vulnerable Code

• The code describes an information leak issue
• It accepts the expiration date of a credit card and incorporates it within the format string

Secure Code

• In the code, it is ensured that user inputs are not incorporated in the format string