Perl CGI Scripts - Form Validation
Errors While Uploading Images Troubleshooting
Form validation fails while uploading images (or no data is written
to the database) - If the combined data submitted to the database exceeds
the value defined for $CGI::POST_MAX, then CGI.pm will often clear the
data for all of the fields prior to passing the info to the script for
processing. This feature is designed to prevent a web attacker from
sending enough data to your script to cause a buffer overflow in an
attempt to gain root access over the web server.
Solution: If the amount of submitted data is valid, then increase the
value for POST_MAX by increasing the number which is entered into the
Submit Size field.