Secure Your Application – PCI DSS Specifications

Monday, 26th January 2009 in Development, Technology by Simon | 5 comments

PCI DSS stands for Payment Card Industry Data Security Standard, and is a worldwide security standard assembled by the Payment Card Industry Security Standards Council (PCI SSC). The PCI security standards are technical and operational requirements that were created to help organizations that process card payments prevent credit card fraud, hacking and various other security vulnerabilities and threats. The standards apply to all organizations that store, process or transmit cardholder data – with guidance for software developers and manufacturers of applications and devices used in those transactions. A company processing, storing, or transmitting cardholder data must be PCI DSS compliant.

Types of Data on a Payment Card

The PCI SSC (Council) is responsible for managing the security standards, while compliance with the PCI set of standards is enforced by the founding members of the Council: American Express, Discover Financial Services, JCB International, MasterCard Worldwide and Visa Inc. Non-compliant companies who maintain a relationship with one or more of the card brands, either directly or through an acquirer risk losing their ability to process credit card payments and being audited and/or fined.

All in-scope companies must validate their compliance annually. This validation can be conducted by Qualified Security Assessors, i.e. companies that have completed a three-step certification process by the PCI SSC which recognises them as being qualified to assess compliance to the PCI DSS standard. However, smaller companies have the option to use a Self-Assessment Questionnaire. Whether this questionnaire needs to be validated by a QSA depends on the requirements of the card brands in that merchant’s region.

The current version of the standard specifies 12 requirements for compliance, organised into 6 logically related groups, which are called “control objectives.”

  1. Build and Maintain a Secure Network
    • Requirement 1: Install and maintain a firewall configuration to protect cardholder data
    • Requirement 2: Do not use vendor-supplied defaults for system passwords and other security parameters
  2. Protect Cardholder Data
    • Requirement 3: Protect stored cardholder data
    • Requirement 4: Encrypt transmission of cardholder data across open, public networks
  3. Maintain a Vulnerability Management Program
    • Requirement 5: Use and regularly update anti-virus software
    • Requirement 6: Develop and maintain secure systems and applications
  4. Implement Strong Access Control Measures
    • Requirement 7: Restrict access to cardholder data by business need-to-know
    • Requirement 8: Assign a unique ID to each person with computer access
    • Requirement 9: Restrict physical access to cardholder data
  5. Regularly Monitor and Test Networks
    • Requirement 10: Track and monitor all access to network resources and cardholder data
    • Requirement 11: Regularly test security systems and processes
  6. Maintain an Information Security Policy
    • Requirement 12: Maintain a policy that addresses information security

Compliance with these requirements can be summarized into 3 main stages:

  • Collecting and storing: Secure collection and tamper-proof storage of all log data so that it is available for analysis.
  • Reporting: Being able to prove compliance on the spot if audited and present evidence that controls are in place for protecting data.
  • Monitoring and alerting: Have systems in place such as auto-alerting, to help administrators constantly monitor access and usage of data. Administrators are warned of problems immediately and can rapidly address them. These systems should also extend to the log data itself –- there must be proof that log data is being collected and stored.

What does this actually mean for web application developers?

It is considerably more expensive and more time-consuming to recover from a security incident than to take preventative measures ahead of time. If you follow the guidelines below, you will go along way to securing you application in line with the PCI DSS regulations. Many of the measures apply to general application security, but since PCI DSS is all about security, they are worth mentioning.

Server-level Security:

  • Separate web- and database-servers on to different physical machines.
  • Secure the web- and database-servers with traditional techniques. Only authorised accounts should have the capabilities to run tasks on the machine. That means not giving admin-rights to the user account.
  • Keep servers up-to-date with the latest patches and software releases.
  • Minimise the number of services running on the server. This means limiting the services to only those required for the web- or database-servers to function.
  • Secure information in transit between servers. This may mean physically securing the network to prevent evesdropping via encryption or obfuscating the data amongst innocuous ‘noise’.
  • Secure the database server behind a firewall.

Application-level Security:

  • Separate ColdFusion, the webserver and database server user accounts. They should never be under the same system account.
  • Create a database user specifically for your ColdFusion datasource and restrict it to only the activities required for the application. The user should not have database-owner rights, access to databases not relating to the application or access to the system tables.
  • Revoke privileges in the ColdFusion datasource definition to prevent the SQL commands CREATE, DROP, GRANT, REVOKE and ALTER.
  • General settings in the ColdFusion Administrator:
    • Check the Disable access to internal ColdFusion Java components option.
    • Check the Enable Global Script Protection option.
    • Add a Missing Template Handler.
    • Add a Site-wide Error Handler.
    • Reduce the Maximum size of post data from 100MB.
    • Enable Timeout Requests, and set to 60 seconds or less.
    • Disable Robust Exception Handling on production servers.

Web Application-level Security:

  • Use secure HTTP to transfer data and/or when logged into ‘administration’ secutions of your web application.
  • Timeout sessions after 15 minutes and on browser close.
  • Provide multi-level login processes. For example, lock the application after 3 failed attempts for a period of 10 minutes.
  • Do not identify whether the username or password are incorrect, simply notify the user that their login failed and that they must try again.
  • Encrypt passwords stored in the database with a standard such as SHA-256 or ’stronger’.
  • Use CAPTCHAs (textual and aural) to prevent automated robots hacking into your application.
  • Run regular penetration tests on your application to identify potential problems.
  • Encrypt credit card information held in the database or other storage mechanism. Only store credit card data in line with the PCI DSS regulations.

Code-level Security:

  • Application.cfc – Set the scriptProtect Application variable to true to enable application-wide cross-site script protection.
  • CFQueryParam – This tag, importantly, verifies the data type of a query parameter and, for RDBMSs that support bind variables, enables ColdFusion to use bind variables in the SQL statement. Bind variable usage enhances performance when executing a cfquery statement multiple times. There are limitations to the use of the cfqueryparam tag. In ColdFusion 7 for example, you cannot use them in queries using the cachedWithin attribute. Similarly, they cannot be used in ORDER BY clauses, although the use of conditional logic should resolve the need for order by variables.
  • Functions – As a rule of thumb, validate all the data being passed into a query prior to it being used. ColdFusion MX 7 saw the introduction of the isValid() function. This function tests whether a value meets a validation or data type rule and can be used to replace a large number of type-specific functions such as isArray(), isBinary(), isBoolean(), isDate(), isNumeric() and isSimpleValue() etc.
  • Stored Procedures – I often favour the use of stored procedures over standard queries. Not only do they add an additional level of performance, they provide an additional level of security; ColdFusion does not do any raw processing of queries in the web code, it simply passes variables down the wire to the database server.

Conclusion

The goal of the PCI Data Security Standard is to protect cardholder data that is processed, stored or transmitted by merchants. The security controls and processes required by PCI DSS are vital for protecting cardholder account data, including the PAN – the primary account number printed on the front of a payment card. Merchants and any other service providers involved with payment card processing must never store sensitive authentication data after authorisation. This includes sensitive data that is printed on a card, or stored on a card’s magnetic stripe or chip – and personal identification numbers entered by the cardholder.

By following the points made above, you will go a long way to meeting the PCI DSS guidelines, whilst also securing your infrastructure and applications in a more general sense.

Caveat: The views and comments written in this article are provided as a guideline. I hold no responsibility for the security of your applications and data based upon the information provided.

Preventing SQL Injection in an AIR Application

Monday, 1st September 2008 in Development by Simon | No comments

SQLite is a mostly ACID-compliant relational database management system contained in a relatively small (~500kB) C programming library. The Adobe AIR runtime includes the SQLite embedded database for use by Adobe AIR applications. This allows applications to run and store data locally and or synchronise the datastore with online repositories.

Applications that depend on user input to create a SQL statement — concatenating the user input to the SQL query — can become vulnerable to SQL Injection attacks, much like those common to web applications.

SQL Injection is a technique that exploits a security vulnerability occurring in the database layer of an application. The vulnerability is present when user input is either incorrectly filtered for string literal escape characters embedded in SQL statements or user input is not strongly typed and thereby unexpectedly executed.

Fortunately, there is a simple solution to the problem: use parameterised SQL Statements. Parameterised statements not only make your applications more secure and run more efficiently, but they also enable you to use objects, rather than literal values, in your queries. SQL injection can’t happen because the parameter values are treated explicitly as substituted values, rather than becoming part of the literal statement text.

Parameters in a SQL statement can be either named or unnamed. Below are examples of both types of statement in ActionScript and JavaScript.

Named Parameters

A named parameter has a specific name that is used to match the parameter value to its placeholder location in the SQL statement text. A parameter name consists of the colon (:) or an at (@) character followed by the variable’s name:

ActionScript 3

var conn:SQLConnection = new SQLConnection();
var stmt:SQLStatement = new SQLStatement();
stmt.sqlConnection = conn;
stmt.text = "INSERT INTO user VALUES(@title, @firstname, @lastname)";
stmt.parameters["@title"] = "Mr";
stmt.parameters["@firstname"] = "Simon";
stmt.parameters["@lastname"] = "Whatley";
stmt.execute()

JavaScript

var conn = new air.SQLConnection();
var stmt = new air.SQLStatement();
stmt.sqlConnection = conn;
stmt.text = "INSERT INTO user VALUES(@title, @firstname, @lastname)";
stmt.parameters["@title"] = "Mr";
stmt.parameters["@firstname"] = "Simon";
stmt.parameters["@lastname"] = "Whatley";
stmt.execute()

Unnamed Parameters

As an alternative to using explicit named parameters, you can also use implicit unnamed parameters. To use an unnamed parameter you simply designate a parameter in the SQL statement using a question mark (?) character. Each parameter is assigned a numeric index, according to the order in which the parameters appear in the SQL statement, starting with index 0 (zero) for the first parameter.

ActionScript 3

var conn:SQLConnection = new SQLConnection();
var stmt:SQLStatement = new SQLStatement();
stmt.sqlConnection = conn;
stmt.text = "INSERT INTO address VALUES(?, ?, ?, ?)";
stmt.parameters[0] = "123 Main Street";
stmt.parameters[1] = "Sometown";
stmt.parameters[2] = "12345";
stmt.parameters[3] = "USA";
stmt.execute()

JavaScript

var conn = new air.SQLConnection();
var stmt = new air.SQLStatement();
stmt.sqlConnection = conn;
stmt.text = "INSERT INTO address VALUES(?, ?, ?, ?)";
stmt.parameters[0] = "123 Main Street";
stmt.parameters[1] = "Sometown";
stmt.parameters[2] = "12345";
stmt.parameters[3] = "USA";
stmt.execute()

Note: Use clearParameters() to empty the statement parameters array; e.g. stmt.clearParameters().

Advantages

  1. Performance – A SQL statement that uses parameters can execute more efficiently compared to one that dynamically creates the SQL text each time it executes. The performance improvement is because the statement is prepared once and then executed multiple times using different parameter values, without needing to recompile the SQL statement. A comparison can be draw with database stored procedures.
  2. Data Typing – Parameters are used to allow for typed-substitution of values that are unknown at the time the SQL statement is constructed. The use of parameters is the only way to guarantee the type (storage class) for a value passed to the database. Using paramters therefore, implies better performance and security. When parameters are not used, the runtime attempts to convert all values from their text representation to a type based on the associated column’s type.
  3. Security – The AIR application is not vulnerable to SQL injections so common to web applications.

How to Protect Your Website from a Malicious Attack

Monday, 18th August 2008 in Development by Simon | 2 comments

Every seasoned developer will know that protecting your website from a hacker is a top priority, whether for your own reputation or for maintaining your company’s reputation and log-term revenue prospects.

Why should you be worried about security?

The Web is changing many of the assumptions that people have historically made about computer security and publishing. As the Internet makes it possible for web servers to publish information to millions of users, it also makes it possible for computer hackers, crackers, criminals, vandals, and other “bad guys” to break into the very computers on which the web servers are running. Once subverted, web servers can be used by attackers as a launching point for conducting further attacks against users and organisations.

It is considerably more expensive and more time-consuming to recover from a security incident than to take preventative measures ahead of time.

This blog post started on the premise of protecting your website from a SQL Injection Attack. However, it is also appropriate to discuss, at a relatively high level, how to secure your server architecture and applications.

Server-Level Security

  • Separate web- and database-servers on to different physical machines.
  • Secure the web- and database-servers with traditional techniques. Only authorised accounts should have the capabilities to run tasks on the machine. That means not giving admin-rights to the user account.
  • Keep servers up-to-date with the latest patches and software releases.
  • Minimise the number of services running on the server. This means limiting the services to only those required for the web- or database-servers to function.
  • Secure information in transit between servers. This may mean physically securing the network to prevent evesdropping via encryption or obfuscating the data amongst innocuous ‘noise’.
  • Secure the database server behind a firewall.

Application-Level Security

  • Separate ColdFusion, the webserver and database server user accounts. They should never be under the same system account.
  • Create a database user specifically for your ColdFusion datasource and restrict it to only the activities required for the application. The user should not have database-owner rights, access to databases not relating to the application or access to the system tables.
  • Revoke privileges in the ColdFusion datasource definition to prevent the SQL commands CREATE, DROP, GRANT, REVOKE and ALTER.
  • General settings in the ColdFusion Administrator:
    • Check the Disable access to internal ColdFusion Java components option.
    • Check the Enable Global Script Protection option.
    • Add a Missing Template Handler.
    • Add a Site-wide Error Handler.
    • Reduce the Maximum size of post data from 100MB.
    • Enable Timeout Requests, and set to 60 seconds or less.
    • Disable Robust Exception Handling on production servers.

Code-Level Security

  • Application.cfc – Set the scriptProtect Application variable to true to enable application-wide cross-site script protection.
  • CFQueryParam – This tag, importantly, verifies the data type of a query parameter and, for RDBMSs that support bind variables, enables ColdFusion to use bind variables in the SQL statement. Bind variable usage enhances performance when executing a cfquery statement multiple times. 
    <cfquery name="qry" datasource="#APPLICATION.dsn#">
SELECT column1, column2, column3
FROM tableName
WHERE column4 = <cfqueryparam value="#variable1#" cfsqltype="cf_sql_bit" />
AND column5 LIKE <cfqueryparam value="%#variable2#%" cfsqltype="cf_sql_varchar" maxlength="200" />
AND column6 IN (<cfqueryparam value="#variable3#" cfsqltype="cf_sql_integer" list="true" />)
</cfquery>

    There are limitations to the use of the cfqueryparam tag. In ColdFusion 7 for example, you cannot use them in queries using the cachedWithin attribute. Similarly, they cannot be used in ORDER BY clauses, although the use of conditional logic should resolve the need for order by variables.

  • Functions – As a rule of thumb, validate all the data being passed into a query prior to it being used. ColdFusion MX 7 saw the introduction of the isValid() function. This function tests whether a value meets a validation or data type rule and can be used to replace a large number of type-specific functions such as isArray(), isBinary(), isBoolean(), isDate(), isNumeric() and isSimpleValue() etc.
  • Stored Procedures – I often favour the use of stored procedures over standard queries. Not only do they add an additional level of performance, they provide an additional level of security; ColdFusion does not do any raw processing of queries in the web code, it simply passes variables down the wire to the database server.

Additional Resources

Are these Contenders for Acquisition by Adobe?

Wednesday, 23rd April 2008 in Strategy, Technology by Simon | No comments

Adobe has progressively been developing an online presence with Buzzword, Share, Brio and Photoshop Express. But the online presence falls short of important spreadsheet and presentation applications.

So who could the contenders be? Here are two extremely promising applications built on the Flash platform:

SlideRocket

SlideRocket LogoSlideRocket is a rich Internet application, built on the Flash platform, that provides for every part of the presentation lifecycle. It integrates authoring, asset management, delivery and analytics tools into a single hosted environment that allows you to quickly create stunning presentations, intelligently manage your assets, securely share your slides, and measure the results.

There are already a number of companies that are striving to be the web-based presentation application of choice, including Google, Zoho and Empressr.

SlideRocket is the first online productivity application that embraces business level features such as collaboration, robust security, dynamic data binding and business integration with applications like Salesforce.com. SlideRocket aims to differentiate itself from other presentation products by including a community marketplace where content and services can be shared and transacted. SlideRocket also embraces the best of the Internet with features like asset tagging, web content mashups, embedded data services and seamless rich media support.

It’s absolutely one of the best presentation creation applications out there. And because it’s built on rich Internet application technologies you can add interactivity and create a cinematic experience that I haven’t seen done any where else.

Ryan Stewart, Adobe’s Rich Internet Evangelist writing in ZDNet – SlideRocket – the king of presentation applications.

SlideRocket - main presentation screenSlideRocket - incorporating videoSlideRocket - adding Flickr to the librarySlideRocket - manipulating images

(click on the images for more detail)

SlideRocket has been designed from the ground up with extensibility and portability in mind as well. To this effect, third party developers will be able to build components into slideshows using the application’s APIs, creating compelling presentations.

You can find more information on the SlideRocket website.

blist

Blist LogoBlist makes it easy for anyone to create private or collaborative databases.

Blist is not alone in the online database market. Zoho DB, DabbleDB and Trackvia are all web-based tools that provide users the ability to create and administer databases.

Although Blist’s simplicity makes it seem like you’re not dealing with anything more complicated than an online spreadsheet, the Blist user interface is actually hiding a complex relational database backend.

Unlike other online database systems, such as Zoho DB, using Blist doesn’t require the user to know SQL to use all it has to offer. This makes Blist great for users who need more than an Excel spreadsheet, but who don’t want to delve into the complexities of a database software application like Access.

Blist BetaBlist BetaBlist BetaBlist Beta

(click on the images for more detail)

Blist’s focus on making database creation and management a straightforward process, built on an always available, rich Internet application suggests it can fill a niche. Demand will prove the depth of such a niche, but if it grabs enough attention from people as regular users, it will become an extremely interesting prospect for acquisition.

You can find more information on the blist website.