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EE579T Network Security 8: Vulnerability Assessment

EE579T Network Security 8: Vulnerability Assessment. Prof. Richard A. Stanley. Overview of Tonight’s Class. Review last week’s lesson Look at network security in the news Vulnerability assessment. Last time. SSL provides a means for secure transport layer communications in TCP/IP networks

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EE579T Network Security 8: Vulnerability Assessment

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  1. EE579TNetwork Security8: Vulnerability Assessment Prof. Richard A. Stanley WPI

  2. Overview of Tonight’s Class • Review last week’s lesson • Look at network security in the news • Vulnerability assessment WPI

  3. Last time... • SSL provides a means for secure transport layer communications in TCP/IP networks • SSL is a commonly used protocol, developed by Netscape, but ubiquitously used in browsers, etc. • The key element of SSL is the handshake protocol • SET not widely used for credit transactions, but the dual signature it introduced is useful WPI

  4. Security in the News • Not-so-secure Shell (SSH) • OpenSSH has a buffer overflow problem! • Fixed in Version 3.1, released last week • The glow on your face... • Researcher claims to be able to recover screen content by examining reflections from user’s face at distances up to 50 meters • Could impact rules on classified computing WPI

  5. More News • BlackBerry gets the raspberry • Researchers using open source software and “gadgets from Radio Shack” able to intercept BlackBerry and Mobitex messages • Not a flaw in the design, but an exploitation of the specification • MyLife worm is back • Attempts to delete Windows system files WPI

  6. And Still More News... • Reduced standards no standards • NeoPoint, San Diego, CA fined $95,000 by the Bureau of Export Administration for exporting 128-bit encryption software to South Korea without a license • Ten counts, in 1998-1999 • Company acknowledged it knew license needed • “... The U.S. Government can and will enforce its export controls on encryption products...” WPI

  7. And Still it Overflows... • Buffer Overflow opens Windows (vnunet) • Windows shell buffer-overflow discovered • If exploited, an attacker could execute malicious code with privileges of the logged in user • outsider could add or delete files, communicate with Web sites or reformat the hard drive • Vulnerability results from unchecked buffer in part of Windows shell that helps to locate missing programs WPI

  8. What do all these security issues have in common? WPI

  9. Thought for the Day “The network is the computer.” Sun Microsystems WPI

  10. Is this quote for real or is it for marketing? • What is typical PC bus speed? • What sort of network data transfer rates can be attained? • What does this mean for the future of networked computing? WPI

  11. Course Projects • Teams • Topics • Schedule Let’s sort this out now. WPI

  12. How To Rob a Bank • Just walk in and demand the money • Where is the bank? • How do you know there is any money? • Where to park the getaway car? • Are there any guards or surveillance devices? • Will you need a disguise? • What kinds of things might go wrong? • What if they say “NO?” WPI

  13. Success Requires Planning • Whether robbing a bank or breaching network security, you need to plan ahead • Planning ahead is known as vulnerability assessment • Acquire the target (case the joint) • Scan for vulnerabilities (find the entry points) • Identify poorly protected data (shake the doors) WPI

  14. Information in Plain Sight • Lots of valuable information is just lying around waiting to be used • telephone directories • company organization charts • business meeting attendee lists • promotional material • The Internet has made having a company web page the measure of being “with it” WPI

  15. Target: FBI WPI

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  27. You get the idea • There is a lot of information out there, and it is readily available to anyone • Good intelligence usually consists of open source material properly collated • Law enforcement used to have special access to this sort of information--now it’s out on the ‘net • Network access speeds up the rate at which good intelligence can be collected WPI

  28. Determine Your Scope • Check out the target’s web page • physical locations • related companies or entities • merger/acquisition news • phone numbers, contact information • privacy or security policies • links to other related web servers • check the HTML source code WPI

  29. Refine Your Search • Run down leads from the news, etc. • Search engines are a good way • FerretSoft • Dogpile • Check USENET postings • Use advance search capabilities to find links back to target • Search on wpi + security gives ~ 2900 hits WPI

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  31. Use the Government • EDGAR • SEC site (www.sec.gov/edgarhp.htm) • Search for 10-Q and 10-K reports • Try to find subsidiary organizations with different names • Think about what your organization has on databases available to the public WPI

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  33. Zero In On The Networks • InterNIC • Organization • Domain • Network • Point of contact • www.networksolutions.com • www.arin.net WPI

  34. Search for wpi.edu WPI

  35. Other Sources • InterNIC has 50-record limit, so… • ftp://rs.internic.net/domain • http://samspade.org/ssw/ • freeware • www.nwpsw.com • Netscan tools • Single copy price = $32.00 • www.ipswitch.com • WS_Ping ProPack = $37.50 WPI

  36. Example: Sam Spade WPI

  37. Query on Found Data • POC • May be (often is) POC for other domains • Query for email addresses -- here are a few from @wpi.edu Amiji, Murtaza (MA3608) murti@WPI.EDU (508) 831-5395 Baboval, John (JBJ116) jbaboval@WPI.EDU XXX-XXXX Ballard, Richard (RBS722) rick@WPI.EDU 508-831-6731 Barnett, Glenn S (GSB14) rhythm@WPI.EDU (315)475-5920 Bartelson, Jon (JB12891) jonb@WPI.EDU (508) 831-5725 (FAX) (508) 831-5483 Berard, Keith (KB2414) keithb@WPI.EDU (508)754-4502 Blank, Karin (KBJ257) blankk@WPI.EDU 203-762-0532 Blomberg, Adam (AB5417) scarpa@WPI.EDU 508-755-7699 WPI

  38. Query the DNS • Insecure DNS configuration can reveal information that should be kept confidential • Zone transfers are popular attack methodologies • nslookup often used • pipe output to a text file • review the text file at your leisure • select potential “good targets” based on data WPI

  39. Map the Network • traceroute • Unix and Win/NT • tracert in NT for file name legacy reasons • Shows hops from router to destination • Graphical tools exist, too • VisualRoute • www.visualroute.com WPI

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  41. Detailed Scanning • Network ping sweeps • Who is active? • Automated capabilities with some tools • ICMP queries • Reveal lots of information on systems • System time • Network mask WPI

  42. Port Scanning • Identify running services • Identify OS • Identify specific applications of a service • Very popular • Very simple • Very dangerous WPI

  43. Port Scan Types • Connect Scan--completes 3-way handshake • SYN--should receive SYN/ACK • FIN--should receive RST on closed ports • Xmas tree--sends FIN, URG, PSH; should receive RST for closed ports • Null--turns off all flags; target should send back RST for closed ports • UDP--port probably open if no “ICMP port unreachable” message received WPI

  44. Identify Running Services • Strobe • Udp_scan (from SATAN) • netcat • PortPro & Portscan • nmap • Using SYN scan is usually stealthy • Beware of DoS results WPI

  45. OS Detection • Stack fingerprinting • Different vendors interpret RFCs differently • Example: • RFC 793 states correct response to FIN probe is none • Win/NT responds with FIN/ACK • Based on responses to specific probes, possible to make very educated guesses as to what OS running • Automated tools to make this easy! • Nmap (www.insecure.ord/nmap/) WPI

  46. Enumeration • Try to identify valid user accounts on poorly protected resource shares • Windows NT • net view • lists domains on network • can also list shared resources • nltest -- identifies PDC & BDC • SNMP • open a telnet connection WPI

  47. Automated, Graphical Tools • Can trace network topology very accurately • ID machines by IP, OS, etc. • Makes attack much easier • Cheops • www.marko.net/cheops/ • Tkined • wwwhome.cs.utwente.nl/~schoenw/scotty/ WPI

  48. Actual Scan Results--Win2K • Performed using Internet Security Scanner • Part of the IIS suite of programs • Can scan both NT/2000 and Unix systems • Runs only on NT/2000 • Scan range (i.e., addresses) user settable • This scan done on a local Win 2000 host with a preconfigured heavy scan WPI

  49. Actual Scan Results--Linux • Again, using ISS • Scanned a Linux host • But, ISS doesn’t run on Linux! • So, ran Win2K and ISS inside VMWare, running on top of Linux • VMWare lets you run one of several O/S from inside it, but they can “see” the underlying computer and O/S WPI

  50. Summary • Attacking a network is no different from robbing a bank; you have to plan if you expect to be successful • There are three basic steps to planning, which is called vulnerability assessment: • Acquire the target (case the joint) • Scan for vulnerabilities (find the entry points) • Identify poorly protected data (enumeration) • This applies if you are inside or outside the protected perimeter! WPI

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