Security+ Guide to Network Security Fundamentals, Third Edition

Security+ Guide to Network Security Fundamentals, Third Edition Chapter 3 Protecting Systems

Objectives Explain how to harden operating systems List ways to prevent attacks through a Web browser Define SQL injection and explain how to protect against it Explain how to protect systems from communications-based attacks Describe various software security applications Security+ Guide to Network Security Fundamentals, Third Edition

Hardening the Operating System Hardening the operating system to resist attacks is often a ________________ approach that involves: ________________ to the operating system Protecting against _______________________ _____________ operating system ___________ Let’s take a look at each of these… Security+ Guide to Network Security Fundamentals, Third Edition

Managing Operating System Updates One of the most important steps in hardening an operating system is to _______________ Due to the increased length and complexity of operating systems ____________________ were introduced Then these vulnerabilities were __________________________________ Software vendors deploy software “fixes” to address vulnerabilities Security+ Guide to Network Security Fundamentals, Third Edition

Managing Operating System Updates (continued) Update terminology Security patch A general software security update ________________ _________________________________________ Hotfix addresses a _______________________ Often may not be distributed outside that customer’s organization Service pack A _______________________________________ _________________________________________ Security+ Guide to Network Security Fundamentals, Third Edition

Security+ Guide to Network Security Fundamentals, Third Edition

Managing Operating System Updates (continued) Patch management techniques- applies to all modern operating systems… 1. Install updates _________________________ Checks, downloads and installs regularly and automatically 2. Download updates automatically but ___________ ____________________________________ 3. Check for updates but ______________________ _________________________________________ 4. Never check for updates What is an incentive to using approach #2 or #3? Security+ Guide to Network Security Fundamentals, Third Edition

Managing Operating System Updates (continued) Automated patch update service Used to ________________________________ instead of relying upon the vendor’s online update service Advantages to an automated patch update service include: Can ________________________ by downloading locally Computers that do not have Internet access can receive updates _____________________________________________ ______________________________________, and obtain reports on what updates each computer needs Security+ Guide to Network Security Fundamentals, Third Edition

Buffer Overflow Protection What is Buffer overflow? Occurs when a ______________________________ in random access memory (_________) _____________ _____________ ____________________________ Extra data overflows into the adjacent memory locations and under certain conditions may cause the computer to stop functioning or have unpredictable results _____________________________________ in order to compromise a computer And point to a memory area that contains the attacker’s malware code See example to follow… Security+ Guide to Network Security Fundamentals, Third Edition

Buffer Overflow Protection (continued) Basic defenses against buffer overflows ________________________________ that will protect against these attacks Use a _____________________________ that makes these attacks more difficult For Windows-based systems, there are two defenses against buffer overflows Data execution prevention (_________) Address space layout randomization (________) Security+ Guide to Network Security Fundamentals, Third Edition

Buffer Overflow Protection (continued) Data Execution Prevention (DEP) Most modern CPUs support an ___ (No eXecute) bit to designate a ________________________ _________________________________ _________________________________________________________________________ Windows Vista allows software developers to enable NX hardware protection specifically for the application software that they develop Security+ Guide to Network Security Fundamentals, Third Edition

Default setting Recommended setting Security+ Guide to Network Security Fundamentals, Third Edition

Buffer Overflow Protection (continued) Address Space Layout Randomization (ASLR) _________ assigns executable operating system code to ________________________ in memory This makes it ___________________________ and take advantage of any functionality inside these executables Also makes it harder to predict where OS functionality resides in memory ASLR is _______________________________ _____________________________________ Security+ Guide to Network Security Fundamentals, Third Edition

Configuring Operating System Protection Most organizations take a ______________ to configuring operating system protections: ___________________ a document that clearly ___________________________ an organization will employ to keep information secure _______________________ - OS ____________ _____________ used for each computer ______________________ – a way of configuring a group of baseline security settings at once _______________________ of security template Security+ Guide to Network Security Fundamentals, Third Edition

Preventing Attacks That Come Through the Web Browser These attacks involve using: Cookies JavaScript Java ActiveX Cross-site scripting Security+ Guide to Network Security Fundamentals, Third Edition

Cookies • Cookies are _________________________________ _________________________________________ • Info gathered based on shopping cart contents, info entered by user, preferences set etc. • Two types of cookies: • ____________________________ created by website _____________________________________ • ________________________ created by a ________________ than the one which attempts to access the cookie • Cookies can pose a _________________ risk • Cookies can be used to track the browsing or buying habits of a user • Defenses against cookies include ________________ ______________________ them once they are created Security+ Guide to Network Security Fundamentals

JavaScript A ___________________________________ A computer programming language ________________ _______________ and __________________________ __________________________________________ When a users access a website, the HTML document and script is downloaded to the user’s computer. Web browser extracts the script from HTML and runs it JavaScript _____________ used to create standalone applications Executes using a Java interpreter Visiting a Web site that ______________________ _________________________ to run on a local computer ___________________________ Security+ Guide to Network Security Fundamentals, Third Edition

JavaScript (continued) Security+ Guide to Network Security Fundamentals, Third Edition

JavaScript (continued) Defense mechanisms in place to prevent JavaScript programs from causing serious harm: JavaScript ____________________ capabilities such as _____________________________________________ But CAN access info available to a browser such as cookies JavaScript has _____________________________ Security concerns remain: JavaScript programs __________________________ _____________________________ or authorization The defense against JavaScript is to ______________ ________________________ Security+ Guide to Network Security Fundamentals, Third Edition

Java Java A ___________________________________ ___________________________ _____________ to create standalone applications Java applet A _______________ stored on a Web server and ____________________________________ along with HTML code Can also be made into hostile programs Security+ Guide to Network Security Fundamentals, Third Edition

Java (continued) Security+ Guide to Network Security Fundamentals, Third Edition

Java (continued) _______________ is a safety mechanism and _______________________________________ Surrounds program and _________________________ __________________________ on a local computer ________________________ allowing hostile applets access to sensitive data on the hard drive Two types of Java applets: _____________ Java applet: program that ___________ _____________________ and by default- run in a sandbox ____________ Java applet: has information proving the program is _________________ and has not been altered Security+ Guide to Network Security Fundamentals, Third Edition

Java (continued) Hostile applet of an attacker trying to obtain login info. NOTE: Warning message Security+ Guide to Network Security Fundamentals, Third Edition

ActiveX Set of technologies developed by ______________ Not a programming language but a _____________ _______________________________________ ActiveX controls Also called ___________________________ Can perform many of the same functions of a Java applet, ___________________________________ Have __________________________________________ Can be signed or unsigned but signing only verifies the signer, _______________________________________ ActiveX poses a number of __________________ Security+ Guide to Network Security Fundamentals, Third Edition

ActiveX (continued) If a computer is shared by multiple users, any user can download an ActiveX control which would be available to all users However, a _________________________ ______________________________________ __________________________ that use ActiveX technology _________________________ mechanisms available in Internet Explorer The defense against ActiveX is to __________ it within the Web browser Security+ Guide to Network Security Fundamentals, Third Edition

Cross Site Scripting (XSS) An attack in which _____________________ into a specific type of dynamic Web page Typically involves using client-side scripts written in JavaScript or ActiveX and social engineering Designed to ____________________________________ ______________________________________________ Targeted to Web sites that dynamically generate Web pages that redisplay (_________) user input that has not been properly validated See next slide for example of username echoed Security+ Guide to Network Security Fundamentals, Third Edition

Cross Site Scripting (XSS) (continued) Echoing used… Security+ Guide to Network Security Fundamentals, Third Edition 28

Cross Site Scripting (XSS) (continued) Cross Site Scripting (XSS) attack steps: <while we go over these steps- see the next three slides- and especially the third one …> 1. An attacker searches for a Web site that redisplays a bad login (See Figures 3-8 and 3-9) 2. The attacker then creates an attack URL that contains the embedded JavaScript commands with a link redirecting the user to the attacker’s website 3. A fake e-mail is sent to unsuspecting users with the attack URL as a modified embedded link in the e-mail 4. The unsuspecting victim clicks on the attack URL and enters his username and password Security+ Guide to Network Security Fundamentals, Third Edition

Cross Site Scripting (XSS) (continued) Good- logon info not redisplayed (echoed) Security+ Guide to Network Security Fundamentals, Third Edition

Cross Site Scripting (XSS) (continued) Echoing used… Security+ Guide to Network Security Fundamentals, Third Edition

Cross Site Scripting (XSS) (continued) Defenses against XSS ________________ _____________________ as well as ______ Webmasters should check that all ___________ _________________________________________________________________________ They also should be sure that all Web services and database software is ____________ to prevent XSS ___________________________________________________________________ Security+ Guide to Network Security Fundamentals, Third Edition

Hardening Web Servers Because of their open exposure, ________ ________________________ for attackers ________ (structured query language) A language _______________________ that is stored in a relational _________________ SQL injection One of the most _______________________ Uses a form of injection like XSS Hinges on an _________________________ __________________ into a dynamic Web page Security+ Guide to Network Security Fundamentals, Third Edition

Hardening Web Servers (continued) 123 or 1=1 In the above SQL injection example, the Password that was entered is a continuation of the SQL statement checking the validity of the information entered. So– with the above “or” addition, the statement to allow Login is: Select ID From User Where UserName = User_Entered_Username and Password = User_Entered_Password or 1 = 1 SQL injection- always makes statement true!! Security+ Guide to Network Security Fundamentals, Third Edition

Hardening Web Servers (continued) Attacks in addition to the SQL injection attack _______________ from the database ____________________________ through function calls _______________ a list of all usernames and passwords Security+ Guide to Network Security Fundamentals, Third Edition

Hardening Web Servers (continued) Security+ Guide to Network Security Fundamentals, Third Edition

Protecting Systems from Communications-Based Attacks Communications protocols and applications can also be vectors for attacks Some of the most common communications-based attacks are: Security+ Guide to Network Security Fundamentals, Third Edition

SMTP Open Relays E-mail systems often use the following two TCP/IP protocols to send and receive messages Simple Mail Transfer Protocol (________) handles _______________ (sent) mail Post Office Protocol (___________ for the current version) handles _____________ (received) mail IMAP (Internet Mail Access Protocol- _______is the current version) A more advanced protocol than POP3 for __________________________________ E-mail remains on the e-mail server Mail can be organized into folders and read from any computer Security+ Guide to Network Security Fundamentals, Third Edition

SMTP Open Relays (continued) SMTP relay SMTP servers can _______________________ ___________________________________ SMTP open relay If SMTP relay is not controlled, an _____________ _______________________________________ The _____________ against SMTP open relay is to _________________________________ So that all users ________________________ ______________________ or limit relays to only local users Security+ Guide to Network Security Fundamentals, Third Edition

Instant Messaging _________________________________________ Can also be used to chat between several users simultaneously, to send and receive files etc Basic IM has several ________________________ IM provides a ____________________________________ Bypasses IM server Attackers can use this direct connection to _______________ __________________________ IM is __________________________ by default so attackers could view the content of messages ________________________________ kept on IM server of the correspondence Security+ Guide to Network Security Fundamentals, Third Edition

Instant Messaging (continued) Steps to secure IM include: Keep the IM server within the organization’s firewall and ____________________________ ____________________________________ Enable ________________________________ ____________________________________ ____________________ messages Security+ Guide to Network Security Fundamentals, Third Edition

Peer-to-Peer (P2P) Networks Uses a _____________________________ ___________________________, so each device simultaneously functions as both a client and a server to all other devices connected to the network For ____________ of audio, video, and data, etc Downloads are entire files from one location ___________________________________ ____________________ using P2P Security+ Guide to Network Security Fundamentals, Third Edition

Peer-to-Peer (P2P) Networks (continued) A new type of P2P network has emerged known as ____________________________ Torrents are _______________________ that ________________ available through a _________ _____________ program operated by the person or organization that wants to ________________________ With _________________________________ BitTorrent _______________________________ __________________ like traditional P2P networks Individual BitTorrent users _________________________ so the entire file comes from a ______________________ Security+ Guide to Network Security Fundamentals, Third Edition

Applying Software Security Applications Software security applications that are commonly installed on systems include: Antivirus Anti-spam Popup blockers Personal software firewalls Host intrusion detection systems Security+ Guide to Network Security Fundamentals, Third Edition

Antivirus Antivirus (AV) software ____________________________ as well as monitor computer activity and _______________________, such as e-mail attachments, that might contain a virus If a virus is detected, options generally include cleaning the file of the virus, quarantining the infected file, or deleting the file Entire hard drive should be ___________________ The _________________ of AV software is that it must be _____________________________ to recognize new viruses AV updates known as ____________________________ Security+ Guide to Network Security Fundamentals, Third Edition

Popup Blockers Popup A _____________________________________ over the Web site that is being viewed Popup ______________ Allows the ________________________________ Can be either a separate program or a feature incorporated within a browser As a separate program, popup blockers are often part of a package known as __________________ ________________________________________ by different types of spyware Updates must be downloaded _________________ Security+ Guide to Network Security Fundamentals, Third Edition

Anti-Spam Spam can be annoying but also pose a __________________ Viruses can be spread through e-mails Four different options that corporations can use to prevent (reduce) spam from reaching the user 1. __________________________________________ A. Install the spam filter with the SMTP server See Figure 3-14 on next slide B. Install the spam filter with the POP3 server See Figure 3-15 – two slides down… Security+ Guide to Network Security Fundamentals, Third Edition

Anti-Spam (continued) Security+ Guide to Network Security Fundamentals, Third Edition

Security+ Guide to Network Security Fundamentals, Third Edition