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Chapter 8. Web Hacking: Google, Web Server, Web App Vulnerabilities, and Web-Based Password Cracking Techniques. Web Server Vulnerabilities. Misconfiguration of Web Server Software Using default web site with default settings OS / App bugs; flaws in code Vulnerable Default Install.
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Chapter 8 Web Hacking: Google, Web Server, Web App Vulnerabilities, and Web-Based Password Cracking Techniques
Web Server Vulnerabilities • Misconfiguration of Web Server Software • Using default web site with default settings • OS / App bugs; flaws in code • Vulnerable Default Install
Attacking a Web Server • Access via Ports 80 and/or 443 • Allow HTTP Tunneling for covert protocols • Banner Grabbing • Opportunities after Banner Grabbing • Knowing the server type and version: • Deface • Gather Admin information • Using DNS to redirect users • Compromise FTP or SMTP • Change web shares • Perform SQL Injection attacks
Hacking IIS • Directory Transversal / Unicode Exploit • Accessing directories other than those intended • http://www.something.com/scripts/scripts/..%co%af../..%co%af../windows/system32/cmd.exe?/c+dir+C.\ • Buffer Overflow attacks • Send more data than capable of handling • Source Disclosure attacks • Collecting web app source code
Web Server Hardening • Rename Admin account; strong password • Disable default FTP sites • Disable Anonymous/Blind FTP: stops directory transversal • Remove unused apps • Disable directory browsing • Apply patches, hotfixes, service packs • Perform bounds checking • Disable remote administration • Enable auditing and logging • Use strong firewall • Replace GET method with POST method
Web Application Threats • Cross-Site Scripting: Replace ‘<‘ and ‘>’ with ‘<’ and ‘>’ • SQL Injection: validate user variables • Eg: SELECT email, passwd, login_id, full_name FROM members WHERE email = 'attacker@somehwere.com'; DROP TABLE members; --‘ • Command Injection: Use language specific variables
Web Application Threats • Cookie Poisoning: no passwords in cookies • Buffer Overflow: validate user input • Vulnerable: C & C++ • Worm: Code Red • Authentication Hijacking: use SSL or TLS • Directory transversal: Set permissions properly
Web Server Hacking Tools • Wget: command-line for downloading entire website • BlackWidow: scan / map pages of a website • MetasploitProject • Metasploit Framework: develop/execute exploit code • Opcode Database • Shellcode Archive • Security Research • http://en.wikipedia.org/wiki/Metasploit_Project
Web Server Hacking Tools • The Way Back Machine • Contains 100+ TB and 10 billion Web pages from 1996 • Httprint: Web server fingerprinting tool • Nitko: Web scanner for penetration testing • WinSSLMiM: HTTPS MitM creates fake certs
Google Hacking • Look for PHP file with ‘admbook’ and ‘version’ • intitle:admbookintitle:versionfiletype:php • Look for particular text: intext: • Search for specific file type: filetype: • http://www.youtube.com/watch?v=_VWXaBq--eg • http://www.informit.com/articles/article.aspx?p=170880 • http://www.marcandangel.com/2007/07/25/7-clever-google-tricks-worth-knowing/
Web-Based Password-Cracking Techniques • Authentication Types • HTTP authentication • Basic: data sent in clear text • Digest: data is hashed and challenge-response is used • NTLM authentication • Used in IIS for NT4 • Kerberos • Used in IIS for 2000 and 2003 and 2008 • Certificate-Based • Uses Public/Private keys • Token-Based • Requires smart card technology • Biometric-Based
Password Attacks / Cracking • Dictionary / Rainbow • Brute-Force • Hybrid • Tools • Brutus: performs Dictionary, Hybrid, Brute-force • Webcracker: uses a word list
Password-cracking Countermeasures • Strong Passwords • Strong Authentication Mechanisms • Kerberos • Tokens • Biometrics