Welcome!

Cloud Security Authors: Harry Trott, Peter Silva, Dana Gardner, Elizabeth White, David Paquette

Related Topics: ColdFusion, Cloud Security

ColdFusion: Article

ColdFusion Security Best Practices

Knowing the security risks are there is half the battle

The Internet has become a scary and hostile place; can your Web applications survive?

Although a lot of media attention has recently been paid to information security, surprisingly little has been published regarding ColdFusion security. Does this then mean that ColdFusion applications are immune to security risks? The answer, unfortunately, is no. Attacks may actually be easier to execute and much more prevalent than programmers would like to believe. Knowing the security risks are there is half the battle.

This article is not meant to be a silver bullet or a complete reference, as that could easily fill many volumes. I hope instead to give a thorough overview of ColdFusion security coding practices - thorough enough that you will know what types of things to take into consideration as you write your applications. Making your applications secure is probably a lot easier than you think.

I will cover some of the more common security problems, such as cross-site scripting, SQL injection, and man-in-the-middle attacks, along with some general ColdFusion security considerations. I will also touch on buffer overflow attacks and authentication and login security.

Cross-Site Scripting (XSS)
Perhaps the easiest type of attack to enact (and the easiest to prevent) against a Web application is that of a cross-site scripting (XSS) attack. Saving a form to the local machine the attacker is working from is the first step in this sort of attack. Once the file is there, the attacker then has the ability to change form field values that would not normally be accessible to a user simply filling out a form, such as radio buttons, select boxes, and hidden form fields, to name a few. The first thing an attacker would have to do is to change the post action of the form to include the full URL of your post page.

Preventing this kind of attack is as easy as checking for a referrer - or even just making sure that the post action is coming from your site. One way to accomplish this is to include code such as the following at the top of your posting pages:


 <!--- XSS Protection --->
 <cfif NOT len(cgi.http_referer) 
    OR NOT findnocase(cgi.http_host,cgi.http_referer)>
       <h3>Post action aborted!</h3>
       <br />
       <p>Post from foreign host detected</p>
       <cfabort>
 </cfif>
This code checks first to be sure that there is a referrer with the "NOT len(cgi.http_referer)". The reasoning behind this is that if the first page they are going to is the posting page, then something is obviously wrong. Also, this is a very real indicator that yes, this is an XSS attack. There can, however, be some false positives with this code because of older browser usage, but this is the fault of the browser and not the code. So at this point we know there is a referrer but not whether it is coming from our server, which is why we include the second part of the cfif statement "NOT findnocase(cgi.http_host,cgi.http_referer)". This section of the statement checks to be sure that this is indeed a page on your site going to post on your site. With this we know that it is most likely a legitimate transaction and will allow the user to post the form.

Note: Be aware of the "www." in your domain when using this code. You may want to alter the code to accommodate all of the possible domains for your site. It is also important to note that there is not a 100% guarantee on the referrer, as this information is sent from the client's browser and is therefore "spoofable."

SQL Injection Attacks
An injection attack is the act of embedding partial SQL queries inside of input that is sent to a WHERE clause in one of your existing queries. A classic (and all too common) example of vulnerable code would look like this:


 <!--- SQL INJECTION VULNERABLE CODE -‡
 <cfquery datasource="#myDNS#" name="qryLogin">
 SELECT * FROM Users WHERE username= '#form.username#' AND
  password='#hash(form.password)#'
 </cfquery>
 <cfif qryLogin.recordCount gt 0>
 	<cfset session.authenticated = 1>
 <cfelse>
 	Invalid login!
 </cfif>
 
To exploit this an attacker would simply have to enter " ' or 1=1--" into the username field. That would produce an end query that looks like this:


 SELECT * FROM Users WHERE username='' or 1=1-- AND password=''
 
As you can see, 1=1 will always be true. The "--" in MS SQL Server will comment out the rest of the query. The resulting record count will be however many records are in the Users table, obviously greater then 0. The user would be logged on and happily browsing your application.

There are a number of things developers can do to reduce the risk of SQL injection attacks in their applications. One technique I like to use is to write a UDF (user-defined function) that will escape out all quotes and then use it as a wrapper for all values passed to the query. Following is a simple example of such a UDF:


 /**
  * UDF that replaces strings commonly used in SQL Injections
  * and replaces them with Unicode equivalents.
  * 
  * Written for September 2004 issue of CFDJ magazine
  * Version 1 by Bryan Murphy, [email protected]
  * Written in cfscript
  * @param string 	 Text to parse. (Required)
  * @return Returns a string.
  * @author Bryan Murphy ([email protected])
  * @version 1, July 22 2004
  */
 function sqlSafe(string) {
   var sqlList = "-- ,'";
   var replacementList =
 "#chr(38)##chr(35)##chr(52)##chr(53)##chr(59)##chr(38)##chr(35)##chr(52)
 ##chr(53) ##chr(59)# , #chr(38)##chr(35)##chr(51)##chr(57)##chr(59)#";
 
   return trim(replaceList( string , sqlList , replacementList ));
 }
 
The simplest way to protect your applications from a SQL injection attack would be to store all of your SQL code in stored procedures. Because a stored procedure does not dynamically create a SQL query, it is not susceptible.

ColdFusion also has the CFQUERYPARAM tag. Using this tag properly will also ensure the safe execution of your SQL queries. Be sure to provide the CFSQLType value to ensure that the data being passed is of the expected type for your database.

Man-in-the-Middle Attack (Session Hijacking)
Using this type of attack, the attacker sometimes sniffs the packets of a legitimate user. The attacker will then alter the packets and send them back at the application on the user's behalf.

The best way to eliminate this risk is by "tying" multiple variables from different scopes together. Require a session, database, and cookie variable to be concatenated and match a session-specific variable. An encrypted or hashed UUID works best for this purpose.

Parameter Manipulation
Another very common type of attack used against a Web application is parameter manipulation. Arguably just about any type of attack could be grouped into this category, but for the purpose of this article I will use this term to refer to attacks by users providing unexpected input into fields they are given access to.

These attacks could range from someone entering ".5" for the quantity of a $100 product and being charged only $50 for it, to someone entering a letter into a field that is expecting a number to see if they can receive an error message.

This type of attack simply comes down to not properly checking user-supplied attributes. If you are expecting a whole number, use the ceiling() function to round entries up to the nearest whole number; if you are expecting any sort of numeric value, use the val() function, which automatically strips out nonnumeric characters.

Your post actions should do a host of error handling and input validation before anything is saved to a database or any access is granted. Your error handling should be done server side. Do not rely on JavaScript or other client-side validation, as these are all easily manipulated by the end user. Be aware that CFFORM fields generate JavaScript validation, making it useless against this sort of attack.

Buffer Overflows
Buffer overflows are by far the most prominently publicized vulnerabilities. Although these are extremely prevalent in normal software, they are not a direct concern for ColdFusion developers, as the ColdFusion Server does not allocate memory at runtime or have pointers. This does not mean that the ColdFusion Server itself is not susceptible to such attacks. The recommended course of action is to subscribe to the ColdFusion security mail list (www.macromedia.com/devnet/security/security_zone/ notification_service.html) and patch appropriately as patches are released.

General ColdFusion-Specific Security Considerations
There are some general things that every ColdFusion programmer should take into consideration. CFFILE, CFFTP, and CFPOP present a unique set of insecurities. Each of these tags allows an end user to write a file to your server. It is important to filter MIME types to exactly what you are expecting. Better yet, allow files to be saved only outside of Web-accessible directories.

In the event of an error, never give away any details (DSNs, table names, directory paths, and so forth) in the error message. Attackers will intentionally throw things at your application in an attempt to generate error messages that will aid them in their attacks.

SSL (Secure Sockets Layer) provides a layer of encryption between the client and the server. If your application stores or transfers any data of a sensitive nature (social security numbers, credit card numbers, etc.) you will need to use SSL. If it's a public site, your users will demand it. Even novice Internet users know to look for the little padlock in the corner of their Web browser; if they don't see it, they take their business to another company.

Authentication/Login Mechanisms
The last security issue I will touch on covers authentication systems and login systems. These systems may seem simple to the average developer, but creating a secure login requires a substantial amount of code. I would recommend putting a lot of time and effort into your login/authentication mechanism and placing it in a CFC or custom tag. Then you can reuse it across all of your applications, and if a problem is found it requires that you change code in only one place for all applications. It's a good idea to use and reuse trusted components. However, if you would prefer an off-the-shelf product, you may try MetaGuard (http://guardianlogic.com/?dna=products&rna=metaguard ). We have written all of the laborious stuff for you.

Always hash/encrypt passwords and other sensitive data. If an attacker is somehow able to get direct access to your database, you don't want them to see all of your passwords in plain text.

Require complex passwords. Time and time again, end users have shown that they are completely content using the name of their pet, child, or even their username as a password. This is gold to an attacker, as it requires only a brief amount of research or one or two guesses to break it. I recommend using some sort of UDF to verify the complexity when a user goes to change or create a password. My favorite is passwordCheck(), which can be downloaded from www.cflib.org/udf.cfm?id=1072

Make passwords expire. This rule is sometimes disregarded, but it is still very important. If an attacker managed to gain a copy of your users table six months ago, he or she will still be able to gain access with those passwords today if you don't require expiration.

Log everything (or at least all that is useful). If someone is hammering an account with 100 invalid login attempts per minute and all you know is that your site is running slow, then your application has a way to go before it can be considered secure. Use CFLOG, write the events to a table in a database, or use CFFILE to write a plain text log file. Any or even combinations of these methods will work. Remember, these logs are useful only if someone actually checks them.

Set a maximum invalid login threshold lockout. In other words, if a user has X invalid login attempts, he or she will be locked out for Y minutes. Some applications require that an administrator unlock an account after a lockout occurs. In my opinion this is not the best method, as it could be used to create a DOS (denial of service) event. It is common for attackers to gather all of the logins they can for a site and run a brute-force or dictionary attack against each one. This will essentially lock out every user on your system (that they have usernames for). This is a nightmare to deal with.

Allow only one connection per user at a time. If someone attempts to log on as a user who is already logged on from a different IP, it should be logged as a security event. The user is either sharing passwords, or his or her password has been compromised.

Write IP-based auto-blacklisting for repeat offenders. This may even be the route you want to go for the invalid login lockout. This way the account itself remains usable by legitimate users, but the attacker's IP is locked out. Of course this does allow the attacker to make an attempt from another IP or to spoof the IP and try again.

As you can see, many security concerns must be taken into account when writing a Web application. It may seem like a lot of extra effort - until you experience your first XSS attack and the attacker makes off with your product for pennies or uses a SQL injection attack to steal your customer database, credit card numbers included.

Security considerations should be included in everything you do. They should be embedded into your thinking and not added as an afterthought.

Resources

  • OWASP: www.owasp.org
  • Search Security: http://searchsecurity.techtarget.com
  • Macromedia CF security: www.macromedia.com/devnet/mx/coldfusion/security.html
  • CF server security announcement list: www.macromedia.com/devnet/security/security_zone/ notification_service.html
  • WASC: http://webappsec.org
  • More Stories By Bryan Murphy

    Bryan Murphy is the owner of GuardianLogic, Inc. (www.guardianlogic.com), an information security firm that provides application and network vulnerability assessments and hardening. He is also one of the authors of Metazoa (www.metazoa.ca), a security-enhanced content management system; Membrane, an application-level firewall; and MetaGuard, a CFC that provides role-based login, authentication, and access control. Bryan has been an ethical hacker since the old-school BBS days. Visit his blog at www.downgrade.org.

    Comments (3) View Comments

    Share your thoughts on this story.

    Add your comment
    You must be signed in to add a comment. Sign-in | Register

    In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


    Most Recent Comments
    Ron K 06/22/07 11:10:54 PM EDT

    Great article. Gave me some good pointers on security issues.

    Michael Johnson 01/18/06 02:35:22 AM EST

    This is a really poor atricle.. your suggesting preventing cross site scripting by checking the referer, wow! Most input fields you can directly inject the code, if that gets stored into a database and re-displayed back to the user I can get whatever information I want.. Also with a combination of http response splitting you can overwrite the header information easily. This article should really be removed or updated correctly.

    somus 04/02/05 12:51:39 PM EST

    I wonder if your paranoia stems from having your hand in the security field? does the fact that you are making money from spreading fear and suspicion keep you up at night?

    I hope you choke on your fat wallet

    @ThingsExpo Stories
    Smart Cities are here to stay, but for their promise to be delivered, the data they produce must not be put in new siloes. In his session at @ThingsExpo, Mathias Herberts, Co-founder and CTO of Cityzen Data, will deep dive into best practices that will ensure a successful smart city journey.
    SYS-CON Events announced today that 910Telecom will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Housed in the classic Denver Gas & Electric Building, 910 15th St., 910Telecom is a carrier-neutral telecom hotel located in the heart of Denver. Adjacent to CenturyLink, AT&T, and Denver Main, 910Telecom offers connectivity to all major carriers, Internet service providers, Internet backbones and ...
    Pulzze Systems was happy to participate in such a premier event and thankful to be receiving the winning investment and global network support from G-Startup Worldwide. It is an exciting time for Pulzze to showcase the effectiveness of innovative technologies and enable them to make the world smarter and better. The reputable contest is held to identify promising startups around the globe that are assured to change the world through their innovative products and disruptive technologies. There w...
    Internet of @ThingsExpo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 19th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devices - comp...
    DevOps at Cloud Expo, taking place Nov 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 19th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait for long dev...
    Data is the fuel that drives the machine learning algorithmic engines and ultimately provides the business value. In his session at Cloud Expo, Ed Featherston, a director and senior enterprise architect at Collaborative Consulting, will discuss the key considerations around quality, volume, timeliness, and pedigree that must be dealt with in order to properly fuel that engine.
    19th Cloud Expo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy. Meanwhile, 94% of enterpri...
    There is growing need for data-driven applications and the need for digital platforms to build these apps. In his session at 19th Cloud Expo, Muddu Sudhakar, VP and GM of Security & IoT at Splunk, will cover different PaaS solutions and Big Data platforms that are available to build applications. In addition, AI and machine learning are creating new requirements that developers need in the building of next-gen apps. The next-generation digital platforms have some of the past platform needs a...
    SYS-CON Events announced today Telecom Reseller has been named “Media Sponsor” of SYS-CON's 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.
    The 19th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Digital Transformation, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportuni...
    With so much going on in this space you could be forgiven for thinking you were always working with yesterday’s technologies. So much change, so quickly. What do you do if you have to build a solution from the ground up that is expected to live in the field for at least 5-10 years? This is the challenge we faced when we looked to refresh our existing 10-year-old custom hardware stack to measure the fullness of trash cans and compactors.
    The emerging Internet of Everything creates tremendous new opportunities for customer engagement and business model innovation. However, enterprises must overcome a number of critical challenges to bring these new solutions to market. In his session at @ThingsExpo, Michael Martin, CTO/CIO at nfrastructure, outlined these key challenges and recommended approaches for overcoming them to achieve speed and agility in the design, development and implementation of Internet of Everything solutions wi...
    Cloud computing is being adopted in one form or another by 94% of enterprises today. Tens of billions of new devices are being connected to The Internet of Things. And Big Data is driving this bus. An exponential increase is expected in the amount of information being processed, managed, analyzed, and acted upon by enterprise IT. This amazing is not part of some distant future - it is happening today. One report shows a 650% increase in enterprise data by 2020. Other estimates are even higher....
    Today we can collect lots and lots of performance data. We build beautiful dashboards and even have fancy query languages to access and transform the data. Still performance data is a secret language only a couple of people understand. The more business becomes digital the more stakeholders are interested in this data including how it relates to business. Some of these people have never used a monitoring tool before. They have a question on their mind like “How is my application doing” but no id...
    Identity is in everything and customers are looking to their providers to ensure the security of their identities, transactions and data. With the increased reliance on cloud-based services, service providers must build security and trust into their offerings, adding value to customers and improving the user experience. Making identity, security and privacy easy for customers provides a unique advantage over the competition.
    I wanted to gather all of my Internet of Things (IOT) blogs into a single blog (that I could later use with my University of San Francisco (USF) Big Data “MBA” course). However as I started to pull these blogs together, I realized that my IOT discussion lacked a vision; it lacked an end point towards which an organization could drive their IOT envisioning, proof of value, app dev, data engineering and data science efforts. And I think that the IOT end point is really quite simple…
    Personalization has long been the holy grail of marketing. Simply stated, communicate the most relevant offer to the right person and you will increase sales. To achieve this, you must understand the individual. Consequently, digital marketers developed many ways to gather and leverage customer information to deliver targeted experiences. In his session at @ThingsExpo, Lou Casal, Founder and Principal Consultant at Practicala, discussed how the Internet of Things (IoT) has accelerated our abil...
    Is the ongoing quest for agility in the data center forcing you to evaluate how to be a part of infrastructure automation efforts? As organizations evolve toward bimodal IT operations, they are embracing new service delivery models and leveraging virtualization to increase infrastructure agility. Therefore, the network must evolve in parallel to become equally agile. Read this essential piece of Gartner research for recommendations on achieving greater agility.
    SYS-CON Events announced today that Venafi, the Immune System for the Internet™ and the leading provider of Next Generation Trust Protection, will exhibit at @DevOpsSummit at 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Venafi is the Immune System for the Internet™ that protects the foundation of all cybersecurity – cryptographic keys and digital certificates – so they can’t be misused by bad guys in attacks...
    For basic one-to-one voice or video calling solutions, WebRTC has proven to be a very powerful technology. Although WebRTC’s core functionality is to provide secure, real-time p2p media streaming, leveraging native platform features and server-side components brings up new communication capabilities for web and native mobile applications, allowing for advanced multi-user use cases such as video broadcasting, conferencing, and media recording.