🔒 fix: use strict comparison in VinNA validation#210
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This prevents unexpected type coercions (type juggling) when validating the check digit of a Vehicle Identification Number (VIN). For example, a valid VIN check digit evaluating to `0` could previously be bypassed with an alphabetic character due to loose comparison (`0 == 'a'` evaluating to true in older PHP versions). We enforce strict comparison by replacing `==` with `===` and explicitly casting the numeric check digit to a string prior to comparison. Co-authored-by: ronanguilloux <313677+ronanguilloux@users.noreply.github.com>
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🎯 What: The vulnerability fixed
A loose type comparison issue (
==) existed insrc/IsoCodes/VinNA.phpwhere a check digit calculated from the VIN was compared to the provided check digit. By replacing this with strict comparison (===) and appropriate type casting, type juggling issues are prevented.Under older versions of PHP (e.g., PHP 7), a computed check digit of
0could evaluate as loosely equal to alphabetic strings like'a'. This allowed maliciously crafted or incorrect VINs that have a computed check digit of0but are provided with an alphabetic character in the 9th position to bypass validation.🛡️ Solution: How the fix addresses the vulnerability
The computed
$checkdigit (which might be an integer 0-9 or string'x') is now strictly compared to10using===. Crucially, when comparing the check digit to the 9th character of the string, the check digit is first explicitly cast to a string(string) $check === $vin[8]. This ensures the exact character value is matched and prevents type juggling evaluation. A test case was also added to ensure this correctly fails.PR created automatically by Jules for task 7232223019106578453 started by @ronanguilloux