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Technical Risk Technical Remediation

Technical Myth

Mike ScherDirector of LabsNeohapsis, Inc.

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Neohapsis 101 - Who we are and what we do

• Information Security Consultancy with an emphasis on R&D and QA/QC

• Network Computing Magazine's Chicago Lab• Producers of the SANS Security Alert

Consensus Newsletter (SAC)• Security Design, Testing, Forensics

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Managing Technical Risks

• Legal Risk Management

Infrastructure Security• Financial Risk Management (Insurance)

• Risk Transfer and Due Diligence

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Technical Risks• Risks to Systems

– Process Disruption– Access to data

• Risks to Data– Data can be disclosed or ‘stolen’– Data can be altered– Data can be destroyed– Data can become unavailable

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How Technical Risks to Data Ripen

Gaps:• Lack of policy

– regarding access to and placement of sensitive data

• Lack of technical access controls – that implement system and data access policies

• Lack of policy verification and enforcement– that audits technical access controls

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How Technical Risks to Data Ripen

Ambiguities or lapses:• Ambiguity or oversight in policy

– from no authoritative source of policy interpretation

• Ambiguity or oversight in application of technical access controls– from no authoritative source of technical policy

planning and review

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How Technical Risks to Data Ripen

Technical failures in access controls• Complexity of technical security systems

– System interactions– Unpredictable failure modes

• Inability to validate security aspects of vendor-provided systems, including security systems– Technical limitations of corporate test groups– Time and materials limitations of testing– Legal limits from statute and license

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Protections for Data• WHO - Authentication systems

– IDs– Passwords– Certificates– Tokens

• WHAT and HOW - Access control / authorization systems– Firewalls (and “intrusion prevention”)– Routers, switches– Operating system controls

• WWHW Review - Audit Systems– Intrusion Detection– Logging– Event aggregation and analysis (SIM)

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AAA

• Authentication systems validate who it is

• Access control systems limit what they can do

• Audit Systems review who did what, when

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Policy is Critical

• Without coordination of Who, What, and How, and the ability to test and audit, security is a matter of reaction

• Reactive security is costly

• Reactive security is ultimately ineffectual

• Policy, well-implemented and reviewed, means proactive security, anticipating needs

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Examples of Technical Risks• External Access Controls

– Too many internal applications open to outside– VPN and dial-up access based on weak access controls– Access to Internal applications dependent on 3rd party’s security

• Online Applications– User account guessing (weak access controls)– Session ID spoofing/guessing– Insufficient input data scrubbing

• “SQL tampering”• Arbitrary command execution• “Cross-site scripting”

• Audit Issues– No or unverifiable history of who accessed what– No ability to monitor copies of data

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Authentication

• User identification– Who do you claim to be?

– Note the use of the term claim

– Examples:• a userid: “jsmither”

• a name: “Joshua Smither”

• a SS#: 111-11-1111

• An e-mail address: jsmither@example.com

– Not always unique, even on the system

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Authentication (cont.)

• User identification + Something else =– Reasonable association of the person with the

ID presented– Why “reasonable”?

• All access controls can be defeated

• Many can be “spoofed”

• Reasonability depends (ideally) on a risk analysis

• What does the ID guard?

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Authentication (cont.)

• PLUS Something else (How can I reasonably assume you are who you claim to be?)– Password– Digital Certificate– “One-time” password (e.g., tokens)– Biometric– ANI (“caller-ID”)– Physical locality (including IP address)– Combinations of techniques

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Problems in Authentication

• Username/Password– Easily stolen when sent “in clear”

– Or via “trojan horse” programs, worms, viruses

– Can be “weak” or “strong” (vs. guessing or “cracking”)• Weak: mouser1 (guessable)

r!verb3d (crackable)

• Strong: 9i63vDvK

– When they are memorable, they are weak

– When they are strong, they are unmanageable

– People almost always either pick weak passwords or they record their passwords someplace handy (perhaps protected by a single password)

– Anyone can use anyone else’s password

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Problems in Authentication (cont.)

• Digital Certificates– Large password protected by a small password– File can be taken just like any other– User’s password to activate the certificate may be

• Guessed• Cracked• Snooped

– More like a “rubberstamp” signature in a locked drawer• But owner may have no indication of its theft• Rebuttable presumption of identity unlikely to ever be rebutted

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Problems in Authentication (cont.)

• Biometrics– Biometrics are static, and easily copied once known

– Never-ending escalation of spoofing tricks against the reader, never-ending need to upgrade readers

– Remote biometric authentication raises issues• Credentials injected into the stream

• Biometric readers use a variety of cryptographic methods to ensure data integrity and reader legitimacy

• At that point, biometrics are a fixed password in a public-key authentication system

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Problems in Authentication (cont.)

• IP addresses (network locality)– Spoofable for some kinds of connections– Don’t establish that the user initiated the action

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Authorization Systems

Essentially Access Control Lists (ACLs)– On Firewalls / IPS– On Gateways and Routers– On Servers– On Workstations

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Firewalls

• Help provide an initial layer of defense at boundaries

• Provide network accounting mechanisms• Can be used as a broad access control

device• Some firewalls can do ACL and pattern-

based content control including virus filtering

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Firewalls (cont.)

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Firewalls (cont.)

• All firewalls are not created equal– Proxy vs. “stateful”

– Proxy vs. Proxy

– Proxy vs. “IPS”

• There is no “best” firewall• Don’t solve host/server-level problems• Have a history of their own security problems• Often provide a false sense of security

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DMZ

Corporate Internal Network

Cat6006 w/IDS HUB

Router

NIDS blade VPN

SQL Database Server Syslog

CSPM

Sniffer

Internal Users

SonicWall HA

Wireless User/Attacker

Wirless Accss Point

WEB

The Big, Bad Internet

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Gateways

• Whose traffic goes where… and how?• Gateways don’t just include firewalls

– Alternate Routers• Wireless

• Dial-up

• Legacy (X.25)

– Virtual Private Network (VPN) gateways

• Any information security program must take all gateways to the corporate network into account.

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VPNs

• VPN:– Simulate a point-to-point, dedicated telco line

as closely as reasonably possible• Identify user or remote network (authentication)

• Limit access (authorization)

• Log accesses and violations (accounting)

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VPNs (cont.)

• Inherently serve one real purpose:– Make doing a very risky thing as safe as

reasonably possible

• Then why do we use them?– Costs– Also, costs– Oh, and costs, too.

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VPNs (cont.)

(Not to mention, costs.)

• The Big Myths about VPNs:– inherently add security– authenticate end-users– ensure authorized use– always less expensive than dedicated telco

connectivity

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VPNs (cont.)

• Risks (especially in connecting a home user to the enterprise network) are significant– Privacy of the connection and authentication traffic

– Theft/compromise of authentication credentials

– End user’s system used as live gateway to private network after the user authenticates

– End user fooled into authenticating to trojan gateway

– Store-and-forward (time-delayed) attacks from compromised end-user system

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Logs (audit trails) and Authentication

• System logs of “who was on what system when” depend on Authentication credentials of the user

• Authentication credentials are often combined for greater assurance– password + biometric + locality– token(one-time password) + password +

locality

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Intrusion Detection Systems

• Misuse detection vs. Anomaly detection

• Host based (HIDS) vs. Network based (NIDS)– HIDS: Active Audit trail monitoring

– NIDS: Snooping network traffic for signs of malfeasance

• Almost all report to a central collection, correlation and alert-generating server

• Useful as an early-warning system and for trending trouble areas

• Useful for some types of after-the-fact damage analysis

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The Upshot• Defense in depth is becoming the new best practice in most industries

– Use firewalls at least at corporate borders– Use IDS internally and at borders– Secure servers and put IT policies in place to maintain their security– Use strong authentication devices for all remote access– Use VPNs with strong authentication and limit remote users’ capabilities

• Defense in depth requires coordinated, intelligent policies, risk analysis, and regular technical review

• Never assume a product is so secure that it is all you need for security – even a firewall

• IT staff need to get and stay up to date, reviewing new issues almost on a daily basis

• Manage IT risks as a part of conducting business

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Questions

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URLs

• Us: http://www.neohapsis.com

• Many security mailing list archives: http://archives.neohapsis.com

• Security Alert Consensus (SAC): http://www.sans.org/sansnews/

• Mike: mscher@neohapsis.com