The wordwrap function in PHP 4 before 4.4.8, and PHP 5 before 5.2.4, does not properly use the breakcharlen variable, which allows remote attackers to cause a denial of service (divide-by-zero error and application crash, or infinite loop) via certain arguments, as demonstrated by a 'chr(0), 0, ""' argument set.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.