Security issue in PHP files
I ran a security test on websecurify tool and its report is giving the following issues:- 

a. 
POST https://stagingeppp.awecommlab.com/select_account.php HTTP/1.1 Content-Type: application/x-www-form-urlencoded

back_from_shopping_cart_flag=Abc123&bundleID=Abc123&new_acc_zip_code=Abc123&new_line_zip_code=Abc123&existing_acct_no=Abc123&upgrade_zip_code=Abc123&upgrade_ph_num1=Abc123&upgrade_ph_num2=Abc123&upgrade_ph_num3=

b. 
POST https://stagingeppp.awecommlab.com/select_account.php?osCsid=hq35ng2rirnltr3jn07d9l4ko5 HTTP/1.1 Content-Type: application/x-www-form-urlencoded

back_from_shopping_cart_flag=Abc123&bundleID=Abc123&new_acc_zip_code=Abc123&new_line_zip_code=Abc123&existing_acct_no=Abc123&upgrade_zip_code=Abc123&upgrade_ph_num1=Abc123&upgrade_ph_num2=Abc123&upgrade_ph_num3=

BTW:- I have tried sanitizing all the values for input elements (Both hidden and visible) before they are set.

Any suggestions are most welcome.
Security issue in PHP files
===

I ran a security test on websecurify tool and its report is giving the following issues:- 

a. 
POST https://stagingeppp.awecommlab.com/select_account.php HTTP/1.1 Content-Type: application/x-www-form-urlencoded

back_from_shopping_cart_flag=Abc123&bundleID=Abc123&new_acc_zip_code=Abc123&new_line_zip_code=Abc123&existing_acct_no=Abc123&upgrade_zip_code=Abc123&upgrade_ph_num1=Abc123&upgrade_ph_num2=Abc123&upgrade_ph_num3=

b. 
POST https://stagingeppp.awecommlab.com/select_account.php?osCsid=hq35ng2rirnltr3jn07d9l4ko5 HTTP/1.1 Content-Type: application/x-www-form-urlencoded

back_from_shopping_cart_flag=Abc123&bundleID=Abc123&new_acc_zip_code=Abc123&new_line_zip_code=Abc123&existing_acct_no=Abc123&upgrade_zip_code=Abc123&upgrade_ph_num1=Abc123&upgrade_ph_num2=Abc123&upgrade_ph_num3=

BTW:- I have tried sanitizing all the values for input elements (Both hidden and visible) before they are set.

Any suggestions are most welcome.