SQL Injection & Cross Site Scripting, by Stefano Santomauro

SQL Injection & Cross Site Scripting

Stefano Santomauro

[email protected]

Stefano [email protected]

• Hacker? Macché• Security engineer? Non so cosa sia

• Appassionato? Forse

• Esperto? Magari!

• ???

Chi sono


Perché questo talk

• Sappiamo da cosa proteggerci?

• Conosciamo il modo in cui difenderci?

• Perché difenderci?

• Quanto costa?

• …


Le vulnerabilità più diffuse sul WEB

OWASP Top Ten Project•A1 - Injection (SQLi e XPATHi)•A2 - Cross Site Scripting (XSS)•A3: Broken Authentication and Session Management•A4: Insecure Direct Object References•A5: Cross-Site Request Forgery (CSRF)•A6: Security Misconfiguration•A7: Insecure Cryptographic Storage•A8: Failure to Restrict URL Access•A9: Insufficient Transport Layer Protection•A10: Unvalidated Redirects and Forwards


SQL Injection: cos’è

«A SQL injection attack consists of insertion or "injection" of a SQL query via the input data from the client to the application»

Fonte OWASP

https://www.owasp.org/index.php/SQL_Injection


SQL Injection: come (1/2)

String username = request.getParameter("username");

String password = request.getParameter("password");

String sql = "select * from users where username = '" +username+"' and password = md5('" +password+"')";


SQL Injection: come (2/2)

select * from users where username = ‘tiziousr’ and password = md5(‘tiziopwd’)

select * from users where username =

‘xxx’ or 1=1 --’ and password = md5(‘tiziopwd’)

SQL eseguita

select * from users where username = ‘xxx’ or 1=1

Commento MySQL


SQL Injection: potenzialità

«A successful SQL injection exploit can read sensitive data from the database, modify database data (Insert/Update/Delete), execute administration operations on the database (such as shutdown the DBMS), recover the content of a given file present on the DBMS file system and in some cases issue commands to the operating system»

Fonte OWASP

https://www.owasp.org/index.php/SQL_Injection


Cross Site Scripting: cos’è

«XSS attacks are a type of injection problem, in which malicious scripts are injected into the otherwise benign and trusted web sites. XSS attacks occur when an attacker uses a web application to send malicious code, generally in the form of a browser side script, to a different end user»

Fonte OWASP

https://www.owasp.org/index.php/Cross-site_Scripting_(XSS)


Cross Site Scripting: come

JSP input

<input type="text" name="username"/>

Servlet

String username = request.getParameter("username");

request.setAttribute("username", username);

JSP output

<span><%=request.getAttribute("username")%></span>

HTML output

<span><script>alert(123)</script></span>


Cross Site Scripting: potenzialità

«[…] the malicious script can access any cookies, session tokens, or other sensitive information retained by your browser and used with that site. These scripts can even rewrite the content of the HTML page»

Fonte OWASP

https://www.owasp.org/index.php/Cross-site_Scripting_(XSS)


DIMOSTRAZIONE…


La dimostrazione continua… a casa

Adesso sta a voi condurre un attacco di tipo XSS.

Scaricate il progetto al link che

trovate nei Riferimenti e, dopo

aver seguito le istruzioni, provate

a trovare le vostre varianti!


Conclusioni (1/4)

La nostra è stata soltanto una semplice “simulazione” di un caso reale…


Conclusioni (2/4)

…ma se anche non volete credere a me, spero crediate a questo…


Conclusioni (3/4)


Conclusioni (4/4)


Riferimenti

• OWASP (https://www.owasp.org/index.php/Main_Page)• md5decrypter (http://www.md5decrypter.co.uk)• Notizia dell’attacco alla SONY (http://www.itwire.com/business-it-news/security/47605-sony-falls-victim-to-another-simple-sql-injection-attack)• Notizia dell’attacco a Skype (https://superevr.com/blog/2011/xss-in-skype-for-ios/)• OWASP WebGoat (https://www.owasp.org/index.php/Category:OWASP_WebGoat_Project)• DOWNLOAD progetto dimostrativo (http://www.divshare.com/download/17108200-6e1)

SQL Injection & Cross Site Scripting, by Stefano Santomauro

Technology

Transcript of SQL Injection & Cross Site Scripting, by Stefano Santomauro