Potential Information Disclosure and Insufficient Entropy in Zend\Captcha\Word
Zend generates a "word" for a CAPTCHA challenge by selecting a sequence of random letters from a character set. The selection is performed using PHP's internal `array_rand()` function. This function does not generate sufficient entropy due to its usage of `rand()` instead of more cryptographically secure methods such as `openssl_pseudo_random_bytes()`. This can potentially lead to information disclosure should an attacker be able to brute force the random number generation.