Injecting Security into vulnerable web apps at Runtime
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Ajin Abraham discusses the integration of security in web applications through Runtime Application Self-Defense (RASD) techniques, highlighting the limitations of traditional Web Application Firewalls (WAF). The presentation emphasizes the need for proactive security measures that focus on precise vulnerability detection and prevention, alongside advanced methods like monkey patching and lexical analysis. Key challenges in application security are outlined, including preventing various types of injection attacks and ensuring minimal performance impact while maintaining application integrity.
Injecting Security into vulnerable web apps at Runtime
- 1. SECURITY ENGINEER AJIN ABRAHAM INJECTING SECURITY INTO WEB APPS WITH RUNTIME PATCHING AND CONTEXT LEARNING
- 2. ▸ Security Engineering @ ▸ Research on Runtime Application Self Defence ▸ Authored MobSF, Xenotix and NodeJSScan ▸ Teach Security: https://opsecx.com ▸ Blog: http://opensecurity.in #WHOAMI
- 3. AGENDA : WHAT THE TALK IS ABOUT? RASP WAF WHAT THE TALK IS NOT ABOUT?
- 4. APPSEC CHALLENGES ▸ Writing Secure Code is not Easy ▸ Most follows agile development strategies ▸ Frequent releases and builds ▸ Any release can introduce or reintroduce vulnerabilities ▸ Problems by design. Ex: Session Hijacking, Credential Stuffing
- 5. STATE OF WEB FRAMEWORK SECURITY ▸ Automatic CSRF Token - Anti CSRF ▸ Templates escapes User Input - No XSS ▸ Uses ORM - No SQLi You need to use secure APIs or write Code to enable some of these Security Bugs happens when people write bad code.
- 6. STATE OF WEB FRAMEWORK SECURITY ▸ Anti CSRF - Can easily be turned off/miss configurations ▸ Templates escapes User Input - Just HTML Escape -> XSS ▸ https://jsfiddle.net/1c4f271c/ ▸ Uses ORM - SQLi is still possible ▸ http://rails-sqli.org/
- 7. STATE OF WEB FRAMEWORK SECURITY ▸ Remote OS Command Execution - No ▸ Remote Code Injection - No ▸ Server Side Template Injection RCE - No ▸ Session Hijacking - No ▸ Verb Tampering - No ▸ File Upload Restriction - No The list goes on…..
- 8. WE NEED TO PREVENT EXPLOITATION LET’S USE WAF
- 9. ▸ First WAF AppShield in 1999, almost 18 years of existence ▸ Quick question : How many of you run a WAF in defence/ protection mode? ▸ Most organisations use them, but in monitor mode due high rate false positives. ▸ Most WAFs use BLACKLISTS CAN A WAF SOLVE THIS? 20% 70% 10% False Negatives False Positive Detection
- 10. APPLICATION SECURITY RULE OF THUMB Gets bypassed, today or tomorrow
- 11. WHAT WAF SEES? ATTACK != VULNERABILITY
- 12. HOW WAF WORKS ▸ The strength of WAF is the blacklist ▸ They detect Attacks not Vulnerability ▸ WAF has no application context ▸ Doesn’t know if a vulnerability got exploited inside the app server or not. WAFGET http://xyz.com APP SERVER HTTP REQUEST HTTP RESPONSE
- 13. ▸ How long they keep on building the black lists? ▸ WAFs used to downgrade your security. ▸ No Perfect Forward Secrecy ▸ Can’t Support elliptic curves like ECDHE ▸ Some started to support with a Reverse Proxy ▸ Organisations are moving to PFS (Heartbleed bug) ▸ SSL Decryption and Re-encryption Overhead WAF PROBLEMS
- 14. TLS 1.3 COMING SOON ….
- 15. SO WHAT’S THE IDEAL PLACE FOR SECURITY? REQUEST RESPONSE APP SERVER APP SERVER CORE SECURITY LAYER
- 16. We can do much better. It’s time to evolve WAF - > SAST -> DAST -> IAST -> RASP Attack Detection & Prevention/Neutralization + Precise Vulnerability Detection + Extras Attack Detection & Prevention Vulnerability Detection Precise Vulnerability Detection
- 17. RUNTIME APPLICATION SELF DEFENCE ▸ Detect both Attacks and Vulnerability ▸ Zero Code Modification and Easy Integration ▸ No Hardware Requirements ▸ Apply defence inside the application ▸ Have Code Level insights ▸ Fewer False positives ▸ Inject Security at Runtime ▸ No use of Blacklists
- 18. TYPES OF RASP ▸ Pattern Matching with Blacklist - Old wine in new bottle (Fancy WAF) ▸ Dynamic Tainting - Good but Performance over head ▸ Virtualisation and Compartmentalisation - Good, but Less Precise, Container oriented and not application oriented, Platform Specific (JVM) ▸ Code Instrumentation and Dynamic Whitelist - Good, but specific to Frameworks, Developer deployed
- 19. FOCUS OF RESEARCH ▸ Other AppSec Challenges ▸ Preventing Verb Tampering ▸ Preventing Header Injection ▸ File Upload Protection ▸ Ongoing Research ▸ Preventing Session Hijacking ▸ Preventing Layer 7 DDoS ▸ Credential Stuffing ▸ RASP by API Instrumentation and Dynamic Whitelist ▸ Securing a vulnerable Python Tornado app with Zero Code change. ▸ Code Injection Vulnerabilities ▸ Preventing SQLi ▸ Preventing RCE ▸ Preventing Stored & Reflected XSS ▸ Preventing DOM XSS
- 20. RASP BY API INSTRUMENTATION AND DYNAMIC WHITELIST ▸ MONKEY PATCHING ▸ LEXICAL ANALYSIS ▸ CONTEXT DETERMINATION
- 21. MONKEY PATCHING ▸ Also know as Runtime Hooking and Patching of functions/ methods. ▸ https://jsfiddle.net/h1gves49/2/
- 22. LEXICAL ANALYSIS AND TOKEN GENERATION ▸ A lexical analyzer breaks these syntaxes into a series of tokens, by removing any whitespace or comments in the source code. ▸ Lexical analyzer generates error if it sees an invalid token.
- 23. LEXICAL ANALYSIS AND TOKEN GENERATION SYNTAX TOKEN int KEYWORD value IDENTIFIER = OPERATOR 100 CONSTANT ; SYMBOL INPUT: int value = 100;//value is 100 Normal Lexer SYNTAX TOKEN int KEYWORD WHITESPACE value IDENTIFIER WHITESPACE = OPERATOR WHITESPACE 100 CONSTANT ; SYMBOL //value is 100 COMMENT Custom Lexer
- 24. CONTEXT DETERMINATION HTML PARSER HTML CODE DOM TREE
- 25. PREVENTING CODE INJECTION VULNERABILITIES Interpreter cannot distinguish between Code and Data Solve that and you solve the code injection problems
- 26. PREVENTING CODE INJECTION VULNERABILITIES ▸ Preventing SQL Injection ▸ Preventing Remote OS Command Execution ▸ Preventing Stored & Reflected Cross Site Scripting ▸ Preventing DOM XSS
- 27. SQL INJECTION SELECT * FROM <user_input>
- 28. SQL INJECTION : HOOK SQL Execution API cursor.execute(‘SELECT * FROM logs‘)
- 29. SQL INJECTION : LEARN SELECT * FROM logs SYNTAX TOKEN SELECT KEYWORD WHITESPACE * OPERATOR WHITESPACE FROM KEYWORD WHITESPACE logs STRING
- 30. SQL INJECTION : PROTECT SYNTAX TOKEN SELECT KEYWORD WHITESPACE * OPERATOR WHITESPACE FROM KEYWORD WHITESPACE logs STRING WHITESPACE AND KEYWORD WHITESPACE DROP KEYWORD WHITESPACE TABLE KEYWORD WHITESPACE admin STRING SELECT * FROM logs AND DROP TABLE admin
- 31. SQL INJECTION : PROTECT KEYWORD WHITESPACE OPERATOR WHITESPACE KEYWORD WHITESPACE STRING Rule for Context: SELECT * FROM <user_input> SELECT * FROM logs SELECT * FROM history SELECT * FROM logs AND DROP TABLE admin KEYWORD WHITESPACE OPERATOR WHITESPACE KEYWORD WHITESPACE STRING WHITESPACE KEYWORD WHITESPACE KEYWORD WHITESPACE KEYWORD WHITESPACE STRING
- 32. DEMO
- 33. REMOTE OS COMMAND INJECTION ping -c 3 <user input>
- 34. REMOTE OS COMMAND INJECTION : HOOK Command Execution API os.system(ping -c 3 127.0.0.1)
- 35. REMOTE OS COMMAND INJECTION : LEARN ping -c 3 127.0.0.1 SYNTAX TOKEN ping EXECUTABLE WHITESPACE -c ARGUMENT_DASH WHITESPACE 3 NUMBER WHITESPACE 127.0.0.1 IP_OR_DOMAIN
- 36. REMOTE OS COMMAND INJECTION : PROTECT ping -c 3 127.0.0.1 & cat /etc/passwd SYNTAX TOKEN ping EXECUTABLE WHITESPACE -c ARGUMENT_DASH WHITESPACE 3 NUMBER WHITESPACE 127.0.0.1 IP_OR_DOMAIN WHITESPACE & SPLITTER WHITESPACE cat EXECUTABLE WHITESPACE /etc/passwd UNIX_PATH
- 37. REMOTE OS COMMAND INJECTION : PROTECT EXECUTABLE WHITESPACE ARGUMENT_DASH WHITESPACE NUMBER WHITESPACE IP_OR_DOMAIN Rule for Context: ping -c 3 <user_input> ping -c 3 127.0.0.1 ping -c 3 google.com ping -c 3 127.0.0.1 & cat /etc/passwd EXECUTABLE WHITESPACE ARGUMENT_DASH WHITESPACE NUMBER WHITESPACE IP_OR_DOMAIN WHITESPACE SPLITTER WHITESPACE EXECUTABLE WHITESPACE UNIX_PATH
- 38. DEMO
- 39. CROSS SITE SCRIPTING <body><h1>hello {{user_input1}} </h1></body> <script> var x=‘{{user_input2}}’;</script>
- 40. CROSS SITE SCRIPTING : HOOK Template Rendering API template.render(“<body><h1>hello {{user_input1}} </h1></body><script> var x=‘{{user_input2}}’; </script>“, user_input1, user_input2)
- 41. CROSS SITE SCRIPTING : CONTEXT DETERMINATION Parsing the DOM Tree <body><h1>hello {{user_input1}} </h1></body><script> var x=‘{{user_input2}}’; </script> HTML_CONTEXT JAVASCRIPT_VALUE_CONTEXT
- 42. CROSS SITE SCRIPTING : PROTECT <body><h1>hello {{user_input1}} </h1></body> <script> var x=‘{{user_input2}}’;</script> <body><h1>hello World </h1></body> <script> var x=‘Hello World’;</script> user_input1 = “World” user_input2 = “Hello World”
- 43. CROSS SITE SCRIPTING : PROTECT <body><h1>hello <script>alert(0)</ script> </h1></body> <script> var x=‘';alert(0);//x3C/scriptx3E’;</ script> user_input1 = “<script>alert(0)</script>” user_input2 = “‘;alert(0);//</script>”
- 44. DEMO
- 45. PREVENTING DOM XSS https://jsfiddle.net/vno23woL/3/ ▸ Inject Security into JavaScript Frameworks ▸ Common JavaScript Frameworks - jQuery, AngularJS, MustacheJS etc… ▸ DOMPurify - https://github.com/cure53/DOMPurify ▸ jPurify - https://github.com/cure53/jPurify
- 46. OTHER APPSEC CHALLENGES ▸ Preventing Verb Tampering ▸ Preventing Header Injection ▸ File Upload Protection ▸ Preventing Path Traversal
- 47. ▸ WAFs blindly blocks TRACE and OPTION Request ▸ Hook HTTP Request API ▸ Learn the HTTP Verbs and Generate Whitelist ▸ Block if not in the list PREVENTING VERB TAMPERING DEMO
- 48. PREVENTING HEADER INJECTION ▸ Unlike WAF we don’t have to keep a blacklist of every possible encoded combination of “%0a” and “%0d” ▸ Hook HTTP Request API ▸ Look for “%0a,%0d“ in HTTP Request Headers ▸ Block if Present DEMO
- 49. FILE UPLOAD PROTECTION ▸ Classic File Upload Bypass image.jpg.php, image.php3 etc. ▸ Hook File/IO API : io.open(“/tmp/nice.jpg”, 'wb') ▸ Learn file extensions to create a whitelist. ▸ Block any unknown file extensions io.open(“/tmp/nice.py”, 'wb') DEMO
- 50. PREVENTING PATH TRAVERSAL ▸ WAF Looks for
- 51. PREVENTING PATH TRAVERSAL ▸ Hook File/IO API: io.open(“/read_dir/index.txt”, ‘rb') ▸ Learn directories and file extensions ▸ Block any unknown directories and file extensions io.open(“/read_dir/../../etc/passwd”, 'rb') DEMO
- 52. ON GOING RESEARCH ▸ Preventing Session Hijacking ▸ Preventing Layer 7 DDoS ▸ Credential Stuffing
- 53. THE RASP ADVANTAGES ▸ Accurate and Precise in Vulnerability Detection & Prevention ▸ Code Level Insight (Line no, Stack trace) ▸ Not based on Heuristics - Zero/Negligible False Positives ▸ No SSL Decryption and Re-encryption overhead ▸ Doesn’t Downgrade your Security ▸ Preemptive security - Zero Day protection ▸ Zero Code Change and easy integration pip install rasp_module import rasp_module
- 54. BIGGEST ADVANTAGE Now you can deploy it on protection mode
- 55. CHARACTERISTICS OF AN IDEAL RASP ▸ Ideal RASP should have minimal Performance impact ▸ Should not introduce vulnerabilities ▸ Must not consume PII of users ▸ Should not learn the bad stuff ▸ Should be a “real RASP” not a fancy WAF with Blacklist. ▸ Minimal Configuration and Easy deployment
- 56. THAT’S ALL FOLKS! ▸ Thanks to ▸ Zaid Al Hamami, Mike Milner, Steve Williams, Oliver Lavery (Team IMMUNIO inc). ▸ Kamaiah, Francis, Bharadwaj, Surendar, Sinu, Vivek (Team Yodlee Security Office - YSO) ▸ Due Credits ▸ Graphics/Image Owners @ajinabraham [email protected]