Transcript Document
Open-Source Network
Security Tools
Scanning/Securing/Exploiting
oh my.
S C I E N C E APPLI CATI O N S I NT E R NAT I O NAL C O R PO RAT I O N
Disclaimer
The opinions expressed in this talk are just
mine, and not the opinions of SAIC, nor ESS.
I have nothing against vendors, some of my best
friends are vendors.
I was asked to do a talk on Open Source
Network Security Tools, and not on commercial
tools to avoid any vendor bias.
They made me do it.
I once saw a ghost cow in the road, honest.
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Agenda
What is Open Source?
Why should I care?
Why no Commercial tools?
What tools are available?
What do they do?
Where can I get them?
Q&A
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What’s OpenSource?
From opensource.org
Open source doesn't just mean access to the source
code. The distribution terms of open-source software
must comply with the following criteria:
1. Free Redistribution
2. Source Code included/available
3. Derived Works allowed
4. Integrity of The Author's Source Code (patches/forks)
5. No Discrimination Against Persons or Groups
6. No Discrimination Against Fields of Endeavor
7. Distribution of License (no NDA)
8. License Must Not Be Specific to a Product
9. License Must Not Restrict Other Software
10. License Must Be Technology-Neutral
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Why does it matter?
Cost
Open Source is free. Zero acquisition cost.
Security
The source code is available for your review.
Many eyes look at code.
Find many bugs.
Patch Often
Support
Free – Web/Mailing-Lists/SIGs
$$$ - Commercial sites/ OS vendors…
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What about freeware / shareware /
trialware etc.
"Freeware" should not be confused with "free
software" (roughly, software with unrestricted
redistribution) or "shareware" (software
distributed without charge for which users can
pay voluntarily).
“Shareware” Software that, like freeware, can be
usually obtained (downloaded) and redistributed
for free, but most often is under copyright and
does legally require a payment in the EULA, at
least beyond the evaluation period or for
commercial applications.
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Why not use commercial products?
How much money do you have?
Why not use these tools at home?
At your sibling’s/nephew’s/parent’s house?
Typically has higher resource needs.
But, has much better support.
Better documentation.
Nice shiny packaging.
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Enough License talk, where’s the
goods?
Categories of tools.
Scanning – To find hosts/targets/details
Accessing – To gauge security and baseline
Securing – To protect the host.
Exploiting – To pants the host.
Deception – To deceive the attacker.
Detection – To detect the attacker
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Scanning (The Basics)
Nmap – Network Mapper
http://insecure.org
OS Detection
Application Detection
High-Speed TCP/UDP scans
IPv4 & IPv6
Supports Unix / Linux / BSD /
Mac OS X, and Windows
Even works with Windows XP SP2!
Extremely configurable and could be a talk by itself…
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Scanning for Wireless
dstumbler
http://www.dachb0den.com/projects/dstumbler.html
AP/SSID detection
Detection of
weped networks
beacon interval for aps
maximum supported rate
Can crack WEP keys.
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Scanning (Advanced)
Paketto Keiretsu 1.10
http://www.doxpara.com/paketto/
Scanrand, an unusually fast
network service and topology
discovery system
Minewt, a user space NAT/MAT
router
Linkcat, which presents a Ethernet
link to stdio
Paratrace, which traces network
paths without spawning new
connections
Phentropy, which uses OpenQVIS
to render arbitrary amounts of
entropy from data sources in three
dimensional phase space.
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Assessing Web Sites
Nikto
http://www.cirt.net/code/nikto.shtml
Web/CGI scanner
Finds vulnerable CGI
Can do IDS evasion
Has over 2,600 checks.
$ nikto.pl –host 192.168.42.27 –verbose –web –output \
> nikto80_192.168.42.27.html.raw
Nikto’s output provides notes on reasons why a finding may be a security risk:
Target IP: 192.168.42.27
Target Hostname: www.victim.com
Target Port: 80
-------------------------------------------------------------------o Scan is dependent on "Server" string which can be faked,
use -g to override
o Server: WebSTAR/4.2 (Unix) mod_ssl/2.8.6 OpenSSL/0.9.6c
o Allowed HTTP Methods: GET, HEAD, POST, PUT, DELETE, CONNECT, OPTIONS,
PATCH, PROPFIND, PROPPATCH, MKCOL, COPY, MOVE, LOCK, UNLOCK, TRACE
o Server allows PUT method, may be able to store files.
o CONNECT method is enabled, server may act as a proxy or relays.
o Server allows DELETE method, may be able to remove files.
o Server allows PROPFIND or PROPPATCH methods, which indicates
DAV/WebDAV is installed. Both allow remote admin and have had
security problems.
o WebSTAR/4.2(Unix)mod_ssl/2.8.6OpenSSL/0.9.6c appears to be outdated
(current is at least mod_ssl/2.8.7) (may depend on server version)
o /public/ Redirects to 'http://www.foundstone.com/public', this
might be interesting...
o robots.txt - This file tells web spiders where they can and cannot
go (if they follow RFCs). You may find interesting directories listed
here. (GET)
o cgi-bin/htsearch?-c/nonexistant - The ht::/Dig install may let an
attacker force ht://Dig to read arbitrary config files for itself.
(GET)
885 items checked on remote host
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Assessing Websites (continued)
pavuk
http://www.idata.sk/~ondrej/pavuk/
Not really assessment.
Very effcient Web Spider
Can copy content off sites
Supports authentication
SSL support
FTP, HTTP, Gopher
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Assessing Passwords
hydra
http://thc.org/thc-hydra/
Brute-Force Password Guesser
Can run in parallel to improve performance.
Is able to assess passwords in…
TELNET, FTP, HTTP, HTTPS, HTTP-PROXY,
LDAP, SMB, SMBNT, MS-SQL, MYSQL,
REXEC, CVS, SNMP, SMTP-AUTH, SOCKS5,
VNC, POP3, IMAP, NNTP, PCNFS, ICQ, SAP/R3,
Cisco auth, Cisco enable, Cisco AAA
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Assessing Networks, Hosts, etc.
Nessus – Security Scanner
http://nessus.org
Uses NMap, Nikto, Hydra,
Server supports Unix *
Clients for Windows & Unix
Has thousands of checks.
Scriptable Attack language
If you don’t use it yet, you should.
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Assessing Wireless
kismet
http://www.kismetwireless.net/
Manufacturer and model identification
Runtime decoding of WEP packets for
known networks
Network IP range detection
Finds hidden SSIDs
Detects wireless attacks
Finds defaults configs.
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Securing Hosts
p0f/pf/iptables
p0f – Passive OS fingerprinting
http://lcamtuf.coredump.cx/p0f.shtml
Can work with pf/iptables to create special rules.
• Only Windows 2000 and newer can connect out
• Restrict in-bound Windows SMTP to 1 per client.
• Only allow OpenBSD SSH to firewall
pf – Berkely Packet Filter
http://www.openbsd.org/faq/pf/
iptables – Linux IP Firewall
http://www.netfilter.org/
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Securing OS through Hardening
Bastille
http://www.bastille-linux.org/
Tightens permissions
Changes to secure defaults
Removes unneeded services
Enables better logging
Locks down subsystems
Is a slicer/dicer
Available for Linux, HP-UX, & Mac-OS.
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Securing Passwords
John the Ripper
http://www.openwall.com/john/
Brute-forces local password files.
Supports
most Unix password file types.
Windows NT/2000/XP LanMan Hashes
OpenVMS and SYSUAF.DAT
AFS/Kerberos v4 TGT
S/Key skeykeys files
Netscape LDAP server passwords
MySQL passwords
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Securing Users/Roles (Advanced)
selinux
http://www.nsa.gov/selinux/
Security Enhanced Linux
Establish MAC (Mandatory Access Controls)
Controls based on Objects not permissions.
Root is not all powerful.
Allows compartmentalized controls.
Really confusing for most mortals.
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Exploiting Switched Networks
Ettercap
http://ettercap.sourceforge.net/
Enables the sniffing and capture of switched networks.
ARP poisoning
Man in the Middle
Passive OS identification
Password capture
Passive Portmap
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Exploiting EndUser Machines
Metasploit
http://www.metasploit.com/
Framework for exploits
Able to execute multiple options vs. a single vulnerability.
32 separate exploits
23 separate shellcodes
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Deceptive Services
dtk – Deception ToolKit
http://www.all.net/dtk/dtk.html
Pretend to run other services.
Pretend to be other OS’s
Prevent the attacker for gaining knowledge
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Deceptive Networks
honeyd
http://www.honeyd.org/
Simulates thousands of virtual hosts at the same time.
Configuration of arbitrary services via simple
configuration file:
Includes proxy connects.
Passive fingerprinting to identify remote hosts.
Random sampling for load scaling.
Simulates operating systems at TCP/IP stack level:
Fools nmap and xprobe,
Simulation of arbitrary routing topologies:
Subsystem virtualization:
Run real UNIX applications under virtual Honeyd IP
addresses: web servers, ftp servers, etc...
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Detecting Network Attacks
Snort with ACID
Snort – Network IDS
http://www.snort.org/
Rules based detection of network threats.
Detects buffer overflows, stealth port scans, CGI
attacks, SMB probes, OS fingerprinting attempts,
and much more.
ACID – Web front-End to Snort
http://acidlab.sourceforge.net/
Enables rapid queries
Displays threats graphically
Uses back-end DB
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Detecting Network Traffic
Ethereal
http://www.ethereal.com/
Not really a Detection, but a GREAT sniffer!
Decodes over 600 protocols
FTP, SMTP, ICMP, RIP,…
Has statistical analysis tools
Allows deep inspection of
network traffic
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Detecting Compromised Boxes
chkrootkit
http://www.chkrootkit.org/
Detects 56 different root-kits
Detects unknown deletions and clean-ups
Works on
Linux 2.0.x, 2.2.x and 2.4.x,
FreeBSD 2.2.x, 3.x, 4.x and 5.x,
OpenBSD 2.x and 3.x.,
NetBSD 1.5.2,
Solaris 2.5.1, 2.6 and 8.0,
HP-UX 11,
Tru64 and BSDI.
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So where can I get this stuff easily?
Many ISO images of bootable linux available.
[P]rofessional [H]acker's [L]inux [A]ssault [K]it
• http://www.phlak.org
Local Area Security
• http://www.localareasecurity.com/
Knoppix security tools distribution
• http://www.knoppix-std.org/
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What about Windows?
Most tools have Windows versions
Nmap, pavuk, ettercap,
Metasploit, etc..
Some are not Open-Source, but are
available for private use
Nessus Windows Technology
• http://www.tenablesecurity.com/newt.html
Others will work under cygwin
Linux/Unix for Windows
http://www.cygwin.com/
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Questions?
This is when you complain that I did not include
your favorite tool.
Or when you tell me what a great time you had.
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Scott C. Kennedy
Chief Engineer, Secure Networking Engineering
4224 Campus Point Court
San Diego, CA 92121
858.826.3035
S C I E N C E APPLI CATI O N S I NT E R NAT I O NAL C O R PO RAT I O N
SANS 2003 Top 20 Vulnerabilities
Windows
1. Internet Information Server (IIS)
2. Microsoft SQL Server (MSSQL)
3. Windows Authentication
(LANMAN)
Unix/Linux
1. BIND Domain Name System
(DNS)
2. Remote Procedure Call (RPC)
3. Apache Web Server
4. Internet Explorer (IE)
4. General Unix Authentication
5. Windows Remote Access Service
5. Clear Text Services (Telnet/ftp/rsh)
6. Microsoft Data Access
Components (MDAC)
6. Sendmail (SMTP)
7. Windows Scripting Host (WSH)
7. Simple Network Management
Protocol (SNMP)
8. Microsoft Outlook & Outlook
Express
8. Secure Shell (SSH)
9. Windows Peer to Peer Sharing
(P2P)
10. Simple Network Management
Protocol (SNMP)
9. Misconfiguration of Enterprise
Services (NIS/NFS)
10. Open Secure Sockets Layer
(OpenSSL)
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SANS 2004 Top 20 Vulnerabilities
Unix/Linux
Windows
1. Web Servers & Services
2. Workstation Service
1. BIND Domain Name System
(DNS)
2. Web Server
3. Windows Remote Access Service
3. Authentication
4. Microsoft SQL Server (MSSQL)
4. Version Control Systems
5. Windows Authentication
5. Mail Transport Service
6. Web Browsers
6. Simple Network Management
Protocol (SNMP)
7. File Sharing Applications
8. LSASS Exposures
9. Mail Client
10. Instant Messaging
7. Open Secure Sockets Layer
(OpenSSL)
8. Misconfiguration of Enterprise
Services (NIS/NFS)
9. Databases
10. Kernel
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