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.
Improper Input Validation 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.