The (1) rand and (2) mt_rand functions in PHP 5.2.6 do not produce cryptographically strong random numbers, which allows attackers to leverage exposures in products that rely on these functions for security-relevant functionality, as demonstrated by

Joomla! 1.5 before 1.5.7 initializes PHP's PRNG with a weak seed, which makes it easier for attackers to guess the pseudo-random values produced by PHP's mt_rand function, as demonstrated by guessing password reset tokens, a different vulnerability t

The search function in phpBB 2.x provides a search_id value that leaks the state of PHP's PRNG, which allows remote attackers to obtain potentially sensitive information, as demonstrated by a cross-application attack against WordPress, a different vu