Apache errors and the approach to solve it Premature end of script headers 500 Internal Server Error The specified CGI application misbehaved by not returning a complete set of HTTP headers. Some troubleshooting tips: i) Check /var/log/apache2/error.log (in ubuntu, check the respective apache error log location for the messages) ii) Check if the content type of the page is correctly set for the html content output. print "Content-type: text/html\n\n"; iii) Check if a valid permission has been given for the file to get executed. The file need permission 755 for it to be executed on the server. iv) Check if the configuration path, inclusion path are set correctly in the referenced programs

Apache Permission Denied Error can be caused due to one of many configuration mistakes listed below Check the apache configuration settings i) The first is the reference to folder where cgi or perl files will reside and its execute permission settings

 <ScriptAlias /cgi-bin/ /usr/local/cgi-bin/>
 <Directory "/usr/local/cgi-bin">
     AllowOverride None
     Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
     Order allow,deny
     Allow from all
 </Directory>

ii) The second is the proper add handlers that are set for the file execution

AddHandler cgi-script .cgi .pl
<Files ~ "\.pl$">
    Options +ExecCGI
</Files>
<Files ~ "\.cgi$">
   Options +ExecCGI
</Files>

Check the apache error log for any messages (/var/log/apache2/error.log).