FirstBlood-#954[COLLAB]vaccination-manager Login page is vulnerable to SQL injection
This issue was discovered on FirstBlood v2

On 2021-10-27, mrrootsec Level 2 reported:

Dear FirstBlood security team, I found a vulnerability on your service. I hope this report will help you.

This bug is found with my collaboration partner mrroot, huge thanks to him


Since Login to Vaccination Management page is vulnerable to SQL injeciton, the malicious user can log in without authentication.

Vulnerability Description(PoC)

This bug is composed of some flaws in login page.

First of all, if we enter a random username like hoge and password like aaa, then User does not exist notification appears.

mrroot discovered that that notification's message is changed to Invalid username or password if we enter username's value as admin. This implies that there is admin account and only password is wrong.

Next, we tried to guess password but failed. Finally, I discovered password param is vulnerable to SQL injection like password=aaa' or 1=1#.

Note: this SQL injection appears only when we input a valid username like admin.

If all things are correct, we can log in without any authentication as admin account.


  • the attacker can bypass authentication and log in as a valid user
  • not only authentication bypass, but also the attacker can extract information from DB by using UNION-base SQL injection

This screenshot shows that we can get the information like there is no table named user in firstblood database. We didn't test more but it's highly possible to apply Time-based SQL injection to extract entire data from DB.

Regards, kinako and mrroot


Endpoint: /vaccination-manager/login.php

Parameter: password

Payload: username=admin&password=aaa' or 1=1#

FirstBlood ID: 30
Vulnerability Type: SQL Injection

There is an SQL injection on the vaccination management portal login page which results in the user being able to login as the administrator.