Awareness of Security Exploits and Their Causes

1. Awareness of Security Exploits and Their Causes Prabhaker Mateti Wright State University Aug – Dec 2014 On Sabbatical at Amrita Viswa Vidyapeetham

2. Some Numbers Security Awareness 2014

3. Amazon.com book search Security Awareness 2014

4. Security Incidents / CERT • 2013: 100000+ • “CERT uses the word "incident" as an administrative term … • A single "incident" can involve anything from a single host computer to a very large number of host computers, at a single site or at hundreds of thousands of sites.” Security Awareness 2014

5. Number of Hosts in the DNS • 2003 171,638,297 • 2000 72,398,092 Security Awareness 2014

6. Sizes of Some Software Security Awareness 2014

7. Bugs per Thousand LOC • Table from “Code Complete” book • Not to be taken as too authentic • Don’t believe the 0 at the low end Security Awareness 2014

8. Terms …

9. “So you got r00ted.’’ • Your machine has been compromised. • root = administrator = super-user • An unauthorized user has obtained root privileges. • A rootkit may have been installed. • Forensic analyses made with tools existing on that system are unreliable. Security Awareness 2014

10. Denial of Service (DoS) • We think of computer systems as providing services to authorized users. • When a system is deliberately made to crash, or made to run legitimate users' programs so very slowly that it is unusable, we refer to it as a "denial of service attack." • The attacker accomplishes this by running certain cleverly composed programs, and is pre-aware of the consequences.  Security Awareness 2014

11. Black Hats v. White Hats • Black hats are the "bad" guys in that they use their knowledge to unauthorizedly break into even more systems, and pass their knowledge to other insiders. • White hats are the "good" guys: they are mostly into forensics and prevention of attacks.  Security Awareness 2014

12. Vulnerability, … • Vulnerability: A weakness that can be exploited to cause damage. • Attack: A method of exploiting a vulnerability. • Threat: A motivated, capable adversary that mounts attacks. Security Awareness 2014

13. Hacker v. Attacker v. Intruder • Hacker = One who programs enthusiastically, even obsessively. • An expert at a particular program, as in ‘a Unix hacker’. • A hacker enjoys exploring the details of programmable systems and how to stretch their capabilities. • A hacker has ethics. Security Awareness 2014

14. Malware • Any “program” that has a “malicious” intent … • Viruses + Worms + Trojans + … Security Awareness 2014

15. Viruses • Viruses are "programs" that modify other programs on a computer, inserting copies of themselves.  • Viruses are not officiallyprograms: • They cannot run on their own. • Need to have some host program. • When the host program is run, the virus runs. Security Awareness 2014

16. Worms • Worms are programs that propagate from computer to computer on a network. • Worms  can run independently. • Worms may have (different) portions of themselves running on many different machines. • Worms do not change other programs, although they may carry other code that does. Security Awareness 2014

17. Trojans • A Trojan mimics the functionality of its namesake legitimate program. • But has a hidden “agenda.” • Ex: wu-ftpd Trojan - Login with specific user/password gives a root shell. Security Awareness 2014

18. Backdoors • Also called trap doors. • Allow unauthorized access to a system. • The absence of backdoors cannot be established. Security Awareness 2014

19. System Security • “System Security” = Computer Security + Network Security • Trojan Horses, Viruses and Worms • Privacy and Authentication • TCP/IP exploits • Firewalls • Secure Configuration of Personal Machines • Buffer Overflow and Other Bug Exploitation • Writing Bug-free and Secure Software • Secure e-Commerce Transactions • … Security Awareness 2014

20. Current practices and their problems

21. Improper Configuration • Out of the box installations are rarely properly configured. • Standard user accounts with standard passwords. • Running unneeded services. • Leaving sensitive files read/write-open. Security Awareness 2014

22. Fortification • Start with a properly configured system. • Delete weak or unneeded components. • Add protective layers. • Keep detailed logs. Security Awareness 2014

23. Hardened OS • Often “equated” with fortification. • Rebuilding an OS from the same source code but by using a more rigorous compiler. • Redesigning portions of an OS. • Statically v. dynamically configured. Security Awareness 2014

24. Rootkits • “A rootkit is a collection of tools and utilities that attackers use to hide their presence and gather data to help them infiltrate further across the network. Rootkits insert backdoors, install Trojans, and patch existing programs.” • Installed after the attacker gains access. • Cannot be detected by firewalls or anti-virus scanners. • 200+ results for search “rootkit’’ on www.packetstormsecurity.org Security Awareness 2014

25. Windows Rootkit Examples • null.sys • HE4Hook • Hacker Defender • Slanret • He4Hook • Vanquish • Fu • … Security Awareness 2014

26. Linux Rootkit Examples • Linux Rootkit (LRK) • TeLeKit • Adore • Knark • t0rnkit • Kernel Intrusion System (KIS) • … Security Awareness 2014

27. Booting Up • BIOS • OS Kernel • Initialization • User logins Security Awareness 2014

28. boot.ini [boot loader] timeout=30 default=multi(0)disk(0)rdisk(0)partition(9)\WINDOWS [operating systems] C:\bootsect\hdc3grub.bin="Booting From FAT32on120GB" multi(0)disk(0)rdisk(0)partition(3)\WINDOWS="Windows XP Pro r0 p3" /fastdetect multi(0)disk(0)rdisk(0)partition(9)\WINDOWS="Windows XP Pro r0 p9" /fastdetect multi(0)disk(0)rdisk(0)partition(14)\WINDOWS="Windows XP Pro r0 p14" /fastdetect C:\bootsect\hdc3grub.bin="Linux via Grub" Security Awareness 2014

29. /boot/grub/menu.lst timeout 10 default 1 title failsafe kernel (hd0,6)/boot/vmlinuz root=/dev/hda7 failsafe devfs=nomount hdc=ide-scsi acpi=off initrd (hd0,6)/boot/initrd.img title linux-smp kernel (hd0,6)/boot/vmlinuz-smp root=/dev/hda7 devfs=mount hdc=ide-scsi acpi=off initrd (hd0,6)/boot/initrd-smp.img title windows root (hd0,0) chainloader +1 Security Awareness 2014

30. Human User Authentication • Something you know • (e.g., a password or other secret); • Something you have • (e.g., smart card, credit card); • Something you are • (e.g., fingerprints, retinal scan, voice print). Security Awareness 2014

31. Passwords • Weak passwords; social engineering. • telnet, ftp, … passwords travel the network in the clear; can be sniffed. • One Time Passwords Security Awareness 2014

32. Cryptography • "Computationally Infeasible” • N = 2^a * 3^b * 5^c * 7^d * ... • One way hash function • takes a variable-length input sequence of bytes and converts it into a fixed-length sequence. • designed to be computationally infeasible to reverse the process Security Awareness 2014

33. Symmetric Keys • sender and receiver of a message share a single, common key. • If ct = encryption (pt, key), then pt = decryption (ct, key). • DES • IDEA • Blowfish Security Awareness 2014

34. Public and Private Keys • a public key known to everyone, and a private or secret key known only to the recipient of the message • The two keys are mathematically related, yet it is computationally infeasible to deduce one from the other. • A global registry of public keys is needed • RSA Security Awareness 2014

35. Man-in-the-Middle Attack • The public key-based communication between say Alice and Bob is vulnerable. • Let us assume that Mallory, a cracker, not only can listen to the traffic between Alice and Bob, but also can modify, delete, and substitute Alice's and Bob's messages, as well as introduce new ones.  Mallory can impersonate Alice when talking to Bob and impersonate Bob when talking to Alice. Here is how the attack works. • Bob sends Alice his public key. Mallory intercepts the key and sends her own public key to Alice. • Alice generates a random session key, encrypts it with "Bob’s" public key (which is really Mallory's), and sends it to Bob. • Mallory intercepts the message. He decrypts the session key with his private key, encrypts it with Bob's public key, and sends it to Bob. • Bob receives the message thinking it came from Alice. He decrypts it with his private key and obtains the session key. • Alice and Bob start exchanging messages using the session key. Mallory, who also has that key, can now decipher the entire conversation. Security Awareness 2014

36. Buffer Overflow “Quick: What's the computer vulnerability of the decade?  It's not the Y2K bug, according to computer science and security analysts, but a security weakness known as the buffer overflow .” • Executable code is injected on to the runtime stack. • The return address that was on the stack is modified to point to the beginning of this code. • The executable code chosen produces a shell. • A root-privileged program is so exploited; so, you are r00ted. Security Awareness 2014

37. Buffer Overflow • Many of the Top 20 vulnerabilities are buffer overflow problems. • Caused by a simple class of programming errors. • C and its promiscuous style. Security Awareness 2014

38. Network Security Ethernet is a broadcast medium. So is: wifi Packet switching. Security Awareness 2014

39. Security of the Connection • Least secure: Wireless networking • Second least secure: Always-on wired connections • Second most secure: Intermittent wired connections (dial-up) • Most secure: Never connected. Security Awareness 2014

40. TCP/IP Design Problems • Designed with too little concern for security. • All data, including various fields in the protocol headers, are sent in the clear. • Sender and Receiver in the packet can be spoofed. Security Awareness 2014

41. IP4 Spoofing • IP address: a.b.c.d, 4-bytes. • IP packet contains the IP addresses of sender and receiver. • Everything in the clear. • IP spoofing replaces the IP address of (usually) the sender or (in rare cases) the destination with a different address. • Services that authenticate based on the IP addresses are vulnerable.  • RPC,  NFS, r-commands (rlogin, rsh, rcp, etc.), X windows, … Security Awareness 2014

42. IP Fragment Attacks • When packets are too large to be sent in a single IP packet, due to interface hardware limitations for example, they can be split up by an intermediate router. • The final destination will reassemble all the fragments of an IP packet. • Attackers create artificially fragmented packets in order to circumvent firewalls that do not perform packet reassembly.  • In the IP layer implementations of nearly all OS, there are bugs in the reassembly code. • Attackers create fragments that trigger these bugs. Security Awareness 2014

43. TCP Exploits • The SYN Flood • Connection Killing by RST • Closing a Connection by FIN • Connection Hijacking Security Awareness 2014

44. Covert Channels • Sending of “data” not in the payload, but via other “places.” • Headers. • Sequence numbers. Security Awareness 2014

45. Probing • Port Scanning is one of the most popular among the reconnaissance techniques. • Find open ports • Fingerprint the OS • Stealth scan, Bounce scan, … • nmap Security Awareness 2014

46. Sniffers • A packet sniffer is a program that eavesdrops on the network traffic. • It copies packets as they pass the NIC. • An NIC in the normal mode reads packets destined to its specific MAC address, and all other packets are ignored. • An NIC in promiscuous mode, receives all packets regardless of the MAC address. Security Awareness 2014

47. Distributed Denial of Service (DDoS) • Several machines participate in a DoS attack of a victim. • These participants are often compromised innocent machines serving the “attacks.” • A remote client triggers the attack servers. Security Awareness 2014

48. DNS Attacks • Domain Name Service protocol is inherently vulnerable. • DNS cache poisoning. • BIND 8 is the most popular DNS server. • DNS servers running BIND are not up to date with security patches and software updates. • On October 21, 2002, 9 of the 13 root name servers were the target of a DDoS attack. Security Awareness 2014

49. Mobile Computing Security Awareness 2014

50. Smart Phones • Highly capable networked computer systems • Quad-core 1.2 GHz CPUs • 1 GB RAM • 16 GB persistent storage • Standard : GSM, Wi-Fi, GPS, Bluetooth, camera, microphone, various sensors • Used by millions of computer-illiterates • Constrained by battery capacity Security Awareness 2014