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Choosing Application Security Tools

There are lots of security tools available, so how do you know which one to pick?

If your security team is not including the application teams in the decision, you run a big risk of failure. The security team does get the ability to form relationships with vendors. We see them at conferences. We know people that work there. Because our focus is on security, we know the tools that exist in our space and we have an idea of which ones may be better than others. Of course, this is often due to what we hear from others, rather than our own experience with those tools.

Picking a tool in a vacuum is less than ideal. Sure, the tool may have five stars and has great detection rates. However, if the tool doesn’t fit into the development process and causes more overhead and friction, it will end up failing. A tool with 100% accuracy is still useless if it is not actually being used.

I have seen over and over where a security group acquires a tool, especially static analysis, and a few months later they realize it is just sitting on the shelf. Like all of us, we are excited when we get a new toy. We use it, learn it. Then, the newness wears off. Without the proper processes in place, this can happen with security tools as well. We don’t want this to happen to you.

The first step in determining which tools make sense is to understand the development process now and where it is going. Lets talk about static analysis for a moment. If your development process doesn’t make use of continuous integration and doesn’t plan to then that is not a high priority feature of the tool you receive. Have you considered what IDE the developers use?

I once had a situation where static analysis was about to be rolled out. The security team worked to pick a vendor and get the ball rolling. It was later in the process that the development team was brought on board with the conversation. They asked questions that were less of a priority to the security team, but more of a priority to them. For example, The tool provided a plugin for their IDE. However, when digging deeper, the plugin ran a few versions behind. So what had appeared to be a good setup, now looked a little less efficient since the plugin may not work. This isn’t a deal breaker, but depending on how you were planning on this solution working, it adds friction to the process. The more friction, the more pain.

The next step is understanding who will ultimately be using this tool? For those that listen to the podcast on a regular basis and follow my blogs, you know I am a huge fan of the application teams having direct access to these tools. In my opinion, static analysis is a developers tool. It is there to evaluate the source code and identify policy violations that only the developer can resolve. Giving them access and control over that function and embedding it into their process reduces that friction. Don’t confuse this with the idea that security is not getting the results. Security still needs to have insight into what is going on with security flaws within the application. But to be efficient, the results of these tools need to fit into the flow of how development works. Not be one-off reports under different processes.

This is no different, in my opinion, than dynamic analysis or interactive analysis. These are tools that should be used by the QA group. The group that is responsible for testing and most likely already has automated testing capabilities. They are trained in identifying bugs, reporting, and tracking them. Building these types of tools into their process just makes sense. How many listeners have their own stories of the security team exporting a thousand page report out of that dynamic scanner and sending it to the application team as a pdf? I have been there. Even I won’t read through that report.

The moral of the story here is that if we don’t understand how development works, what type of tools they already use, and what they can handle, we will probably pick a solution that will be ineffective, or at the very least, cause us a lot more work. The goal is not to just shove tools onto the development teams and say do this. As application security representatives, our goal is to help build better applications. That doesn’t mean that our job is to run all the tools and hound the application teams to fix items. By understanding the environments and processes we can pick tools that will fit much better, allowing us to focus our time on building out other solutions or processes for the organization. We are still relied upon to provide the expert advice and guidance to the issues that are identified.

If you are considering implementing these types of tools, take a moment to sit down with all involved parties to get everyone on board. A well laid out plan will go much further than a shotgun approach.

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OWASP 2017 Changes

When I talk to people about application security, the most recognized topics is the OWASP Top 10. If you haven’t heard of the top 10, or need a refresher, you can get the full list at:

https://www.owasp.org/images/7/72/OWASP_Top_10-2017_%28en%29.pdf.pdf

The OWASP Top 10 is on a three year update cycle. We had the list in 2010, 2013 and now the latest is 2017. You may be wondering why it is 2017 rather than 2016. I think that is a question a lot of people had. In any case, the list made it out to final release after the initial draft was rejected. Now that it is here, we can analyze it and see how it affects us and our organizations.

https://www.youtube.com/watch?v=kfDuxwFScOE

What I think sticks out more to me this update over previous updates is the removal of some pretty common flaws based on my experience. In the past we have seen flaws move up or down on the risk level, or get combined, but not as much removed. In 2017, we saw two items get removed:

  • Cross-site Request Forgery
  • Unvalidated Redirects and Forwards

I find these items interesting because I see them on most of the assessments I do. Let’s take a quick look at them.

Cross-site Request Forgery

CSRF can be a pretty serious flaw based on its context. It is the ability to force the victim’s browser to make requests to another site they are authenticated too without their knowledge. An example of a higher-risk context is the ability to change the victim’s email address on their profile. If the system doesn’t have two factor authentication or other safe guards, changing the email address can lead to the ability to request a password reset. In many situations, this can lead to easily taking over the victim’s account.
This is just one example of how CSRF can be used. The good news is that many newer frameworks provide some level of CSRF protection built-in. So in many applications it is not as prevalent. However, based on my experience, not everyone is using the latest frameworks. Due to this, I still find this on a lot of the assessments I do.

Unvalidated Redirects and Forwards

Unvalidated Redirects is often viewed as a low risk issue. In many cases, it may represent a low risk. There are some situations that make unvalidated redirects fairly dangerous. A good example is the redirect often performed by login forms. A common feature of many applications is to redirect the user to a specific resource after logging in. To do this, a parameter in the URL specifies the path to be sent to. If the application allows redirecting to external sites, it is simple to set up a malicious site with the same look and feel as the expected site. If the victim uses your link with the reference to your malicious site they may be presented with your fake login page after successfully logging into the real site. The victim may believe they have mistyped their password and just login again without checking the URL, leading to account takeover.

We also saw to access control findings get merged into one. This change makes a lot of sense when you look at each item. They are both regarding access control issues.

With the removal and merging, the list has brought on three new vulnerabilities:

  • XML External Entities (XXE)
  • Insecure Deserialization
  • Insufficient Logging and Monitoring

XML External Entities (XXE)

XML External Entities is a vulnerability that takes advantage of how XML Parsers interpret the supplied XML. In this case, it is possible to reference other resources outside of the XML document. A common scenario is the ability to read other files on the web server, such as the /etc/passwd file. This vulnerability also may allow a denial of service attack to occur due to embedding specific entities. This vulnerability obviously relies on the application parsing XML data. If your application is parsing XML, it is recommended to make sure the parser is ignoring or blocking DTDs. If your parser doesn’t have that option, or you need to allow some DTDs, make sure your input validation is limiting those to only acceptable ones.

Insecure Deserialization

Insecure Deserialization occurs when you are deserializing data that has not been properly sanitized. This occurs because we assume that the data serialized has not been modified. When the data is modified, it could be executed during the deserialization process to perform commands. To help prevent this, make sure you are enforcing strict data checks on the objects that have been serialized. I do not see this very often in many of the assessments I do. Just depends on the application as many do not use much serialization.

Insufficient Logging and Monitoring

When I talk to people and ask them about logging, the first response, or usually the only response, is related to troubleshooting. There is no doubt that troubleshooting is critical for any application. If the application is not running as expected, users may leave, transactions may get lost, or a myriad of other issues may occur. Logging is for much more than just troubleshooting. Proper logging of security related events can help identify an attack while it is occurring as well as help identify what happened after the fact. It can be very difficult to identify what data was accessed or how if there are no logs indicating such information. It is good that we are seeing more attention called to this practice, although it can be a complex one to implement and verify. Don’t forget that once you start logging security events, they must be monitored to take action.

Wrap Up

Changes to the OWASP Top 10 isn’t something new. We know it will happen and it may require some adjustment to what we are doing internally. While we do see items drop or get added, it just highlights that the top 10 is a mere starting point of security. Every organization should have their list of top 10 risks. Don’t limit yourself to these short lists. They are to help identify the highest risks and implement them in a feasible way. Application security doesn’t happen overnight. There has to be a starting point and then a path to mature.

Listen to the podcast on this topic. http://podcast.developsec.com/developsec-podcast-91-owasp-top-10-2017-thoughts

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Two-Factor Authentication Considerations

There was a recent article talking about how a very small percentage of google users actually use 2-factor authentication. You can read the full article at http://www.theregister.co.uk/2018/01/17/no_one_uses_two_factor_authentication/

Why 2-Factor

Two-factor authentication, or multi-factor authentication, is a valuable step in the process to protect accounts from unauthorized users. Traditionally, we have relied just on a username/password combination. That process had its own weaknesses that many applications have moved to improve. For example, many sites now require “complex” passwords. Of course, complex is up for debate. But we have seen the minimum password length go up and limitations on using known weak passwords go up. Each year we see lists of the most common passwords to not use, some being 123456 or Password. I hope no one is using these types of passwords. To be honest, I don’t know of any sites I use that would allow this type of password. So many these days require a mix of characters or special characters.

The above controls are meant to help reduce the risk of someone just guessing your password, there are other controls to help try to limit brute forcing techniques. Many accounts offer account lockout after X number of invalid attempts. There are other controls that we also see implemented around protecting the username/password logic. None of these controls help protect against a user reusing passwords on another site that may be compromised. They also do not protect against a user falling for a social engineering attack to trick them into sharing their passwords. To help combat this, many sites will implement a second factor beyond username/password.

The idea of the second factor is that even if you have the username and password, you will not have this other piece of information. In most cases, it is a value that changes every 60 seconds or so, and is delivered over a protected channel. For example, the token used may be sent via SMS, a voice call, or created through a phone application like the Google Authenticator application. So even if the attacker is able to get your password, via a breach, brute force, or just lucky guessing, in theory they would not have access to that second factor.

Why Are People Not Using It?

So why do people not enable the second factor on their Google accounts? Unfortunately, the presentation didn’t appear to explain that, which makes sense since it is difficult to know why people do or do not do certain things. I think there may be a few reasons for it that we will briefly touch on.

First, I think many people just are not aware of enabling the second factor. To be fair, it is sort of buried down in settings that may be difficult to find if you are not really looking for it. If it is not front and center, then there is a much smaller chance people will go seeking it out. To add to the issue, many people really don’t understand what 2-factor authentication means or how it really helps them. Sure, in security we get it, but that doesn’t mean everyone else does. How do we make it more prominent that this is a positive security feature? Many users will already be aware of 2-factor if they use online banking as most of those have started enforcing it.

Many people think that two factor authentication is a burden or it will slow their access down. This is usually not the case unless the application has implemented it poorly. Many sites will allow you to save your computer so you don’t need to enter the 2nd factor every time you access the site. However, it will require it if you access from a different computer.

To complicate things, other applications may not support signing in with 2 factors, like your email client. In these cases, you have to generate an app password which can be very confusing to many users, especially those that are not technically savvy.

There may be a chance that users don’t think they need to protect their email accounts, that it is not sensitive. If you just use email to communicate with friends and receive junk mail, what could be so bad, right? Most people forget that things like password resets are performed using an email account. Having control of an email account provides a lot of control over a lot of things. While it may seem small, email is an important function to protect.

If you are using Gmail, I recommend configuring 2-factor authentication. The following video walks through setting it up using SMS (Although there are other options as well):

Demo- Google 2 factor

If you are developing applications, I recommend looking into providing the option of 2-factor authentication. When you do this, make sure that you are promoting its use in a positive way. If you already have 2-factor with your application, can you run a report to determine what percentage of users are actually using it? If that number is low, what steps can you take to increase them?

Don’t assume that any application is not worthy of the extra security. Many applications are already providing 2-factor and that number will just increase. While we still have the password, we will always be looking for ways to add more protection. When implemented properly, it is simple for the end user, but effective in increasing security. If your user base is not taking advantage of the option, take the time to assess why that is and how it can be improved.

As I was writing this up, I ran into an interesting situation with 2-factor that sparked some more thoughts. When looking to support 2-factor authentication and not using SMS, take careful consideration to the applications you may choose to support. On the Apple App Store alone there are over 200 different authenticator apps available. Some are interchangeable while others are not. This can be another barrier in users choosing to enable 2-factor authentication.

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Tinder Mobile Take-Aways

While browsing through the news I noticed an article talking about the Tinder mobile app and a privacy concern. You can read the article at https://www.consumerreports.org/privacy/tinder-app-security-flaws-put-users-privacy-at-risk/. To summarize what is considered the issue is that the mobile application does not transmit the photos that you see using HTTPS. This means that anyone on the same connection can see the traffic and, ultimately, see the photos you are presented. From my understanding, it doesn’t appear the potential attacker can tell who the user is that is viewing these photos as the rest of the traffic is properly using HTTPS.

We have discussed the move to all HTTPS multiple times on this blog and we are seeing a lot of sites making the switch. With web applications it is easy to see if the site is using HTTPS or not with the indicators near the address bar. Of course, these indicators are often confusing to most, but at least we have the ability to see the status. With a mobile application it is much more difficult to tell if data is transmitted using HTTPS or not because there is no visible indicator. Instead, one needs to view the raw traffic or use a web proxy to see how the data is transmitted. This can be misleading to many people because the assumption is that the data is protected because it is hidden under more layers.

In this instance, the ability to see these photos may not be considered that sensitive by many. Assuming that anyone can create an account and see the photos doesn’t make them a secret. People have opted to post their images for others to find them on the network. Of course, level of sensitivity is in the eye of the beholder these days. Another issue that is potentially possible in this situation is that the attacker could manipulate that image traffic to show a different image. This could lead to the end user seeing a different image than the one expected. The usefulness of this could be called into question at any type of large scale.

The take-away here is that when we are building applications we must take care in understanding how we are transmitting all of our data to determine what needs to be protected. As I mentioned, there is already a push to make everything HTTPS all the time. If you have decided not to use HTTPS for your connections, have you documented the reasons? What does your threat model tell you about the risks with that data and its communication. How does that risk line up with your acceptance procedures.

Another interesting tidbit came out of the article mentioned above. In addition to seeing the actual photos, they found it was possible to identify whether or not the end user liked or disliked the photo by comparing the network traffic. The interesting part about this part is that those decisions were encrypted when transmitted. The key point here is that the traffic for each decision was a set size and the sizes were different for like and dislike. By viewing the traffic after seeing a photo, it is possible to determine which ones were liked based on the size of the requests. In this case, it still doesn’t identify the end user that is using the application.

We don’t typically spend a lot of time analyzing the size of the requests we send in the event someone may try to determine what actions we are taking over an encrypted channel. Most of the time these actions are not possible to determine, or the level of effort is way above what is realistic. The easy solution would be to make sure all traffic was encrypted and we wouldn’t be able to know what images were liked or disliked. Maybe it would be possible to still see the difference, but with no way to tie it to specific images. The other option is to attempt to pad the requests so that they are all the same size. This would be for highly sensitive systems as the complexity may not be worth the benefit.

Of course, all of this is based on the attacker being on the same network as the end user so they can intercept or view the traffic in the first place. In the case of a public place, it might just be easier to hover over your shoulder and watch you use the app then intercept the traffic and guess at who is using it.

Both of these topics are good conversation starters within your organization. They help us realize that even just one request that doesn’t use HTTPS may be seen and could raise an issue. It also helps us to see that sometimes even encrypted data can be determined, but that doesn’t mean it is a high risk. Each situation is different and should be properly analyzed to determine the risk it creates for the company and the organization.

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Remember Me Features

Tired of constantly logging into your applications? Don’t you wish they would just remember you each time you visit, logging you right in? It isn’t as always easy to achieve such a status. There are multiple ways remember me can be implemented. Lets take a look at some of them.

Remember UserName

One of the most common ways for a site to implement the remember me functionality is to remember the username only. The username is typically stored in a cookie on the client’s computer. Remembering the username helps speed up the authentication process, but doesn’t eliminate it. The user still has to enter their password to gain access to the application. Although this is a common technique, some organizations may have data classification policies that don’t allow displaying the username in the application. This can also carry over to the username and the login screen. For these organizations, they may not implement a remember me feature at all. Remembering the username does contain some risk, as it instantly provides the username to an attacker on the user’s computer. This leaves just the password for the attacker to determine, which may be feasible if the user re-uses passwords that have been previously breached.

Long-term Auth Cookies

Another common technique for remembering a user is to set an authentication cookie that has a long life. Once you login, a cookie is created that may not expire for a year or longer. This allows you to be automatically logged in each time you visit the site. I am sure you can think of a few sites that provide this functionality. It is common among some of the social media sites people visit all the time. This is not recommended for any type of sensitive applications because it would allow immediate access to anyone that gains access to the user’s device.

Storing Password Locally (Remember Password)

Another option, that probably shouldn’t be an option, is storing the password on the user’s computer. This was recently seen on a web application, however we won’t mention the site that did this. We can, however learn from their decisions. In the application, they used CryptoJS to encrypt and decrypt this type of sensitive data. In this case, they stored the password in a cookie. With the encryption routines available on the client, it is possible to use them to decrypt the encrypted password with very little effort. This is typically the case any time the routines are made available, especially if the keys are available as well. While I am sure this was done with good intentions, the implementation is not very secure. As a matter of fact, it provides more of a false sense of security. This is most likely due to the use of encryption. It is not recommended to perform this type of encryption client-side, nor is it recommended to store the user’s password on the client like this.

What Next?

There are multiple options to help ease the burden of frequently logging into an application. Depending on the type of application, data stored, and sensitivity of the transactions, the options should be considered carefully. Providing the option to remember a username is convenient with some residual risk. Keeping a user logged in for extended periods of time increase the risk, but may be acceptable depending on the application and its use. Stay away from storing the user’s password locally on the computer they are using. Secure implementation is not easy or straightforward, increasing the risk levels.


Jardine Software helps companies get more value from their application security programs. Let’s talk about how we can help you. James Jardine is the CEO and Principal Consultant at Jardine Software Inc. He has over 15 years of combined development and security experience. If you are interested in learning more about Jardine Software, you can reach him at james@jardinesoftware.com or @jardinesoftware on twitter.

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When One Testing Solution Isn’t Enough

Go to any conference, attend some webinars, or just do a search for application security testing solutions and you can quickly see the sheer number of solutions out there. As in every situation, there are some that are great and some that are not so great. With such great marketing, it is often very difficult to determine what is the best solution. All too often people are looking for that silver bullet. That one testing tool or pen testing company that will find everything. Unfortunately, that solution doesn’t exist, or I just haven’t seen it.

Application testing usually falls into two categories: Automated scanning and manual assessments. To break that down further, automated scanning is broken down into two disciplines: Static and dynamic.

Static Analysis

Static scanning means that code is scanned without running it. Here is a quick post about static analyzers. Inputs are traced through the code to see what paths are taken and determine vulnerabilities. Static scans can be efficient at finding flaws such as cross-site scripting, injection flaws, configuration issues, etc. Static scans excel at finding code issues like hard coded passwords, cryptography issues, and other items not possible through a dynamic or manual test. They still do not do very well at finding business logic flaws which can be the most devastating.

Dynamic Analysis

Dynamic scanning means that the application is scanned as it is running. Unlike a static scan, it can be very difficult to identify hard coded passwords or cryptographic issues because they are not visible to the end user. Dynamic scans do a decent job of identifying other flaws such as cross-site scripting, injection flaws, insecure cookies, and some other configuration issues to name a few. Dynamic scanners do not do a good job identifying authentication, authorization, or business logic flaws in general. Properly tuned scanners may be able to do this, but that requires extra work.

Manual Assessments

Manual assessments are mostly a manual process of analyzing source code or using the application to find security flaws. Source code review, has many advantages of the static scanning mentioned above. Penetration testing is very similar to the dynamic scanning mentioned. In both cases, the testing is done manually vs. using just an automated tool. Manual assessments (pen tests) are much more efficient at finding authentication, authorization and business logic flaw types. Of course the quality of the assessment is heavily influenced by the skill of the person doing the assessment.

Some of the big vendors have started offering all three types of assessment for their customers. The big players (White Hat Security, VeraCode, HP, etc.) all offer static, dynamic and manual assessments for your applications. And with good reason. If you have worked in an enterprise where you are required to have multiple assessments by different groups you quickly realize how nothing provides a complete solution. Each assessment paints a portion of the security picture. Items found by one may not be found by the other. In some instances you may think that two should have found the same item, but that is the nature of security.. No one finds everything.

Multiple Solutions

While you may think that it is overkill to have multiple scanning solutions or testers looking at an application, they all bring a different viewpoint and help identify different types of vulnerabilities. Sort of like an enhanced second pair of eyes. Not only can they double check the work the other has done, but in may situations they can identify different types of vulnerabilities. Not only do different solutions find different vulnerabilities, they also find them at different phases of the development lifecycle. It is common to use the static scanners in the development phase. Dynamic scanners are more commonly seen in the verification phase. Manual assessments, especially 3rd party penetration testers, are also in the verification phase, but near the end of the cycle. The closer to development a flaw is found, the quicker it is to remediate it.

The right solution is the one that fits your environment. Take the time to analyze your setup to determine the best way to implement a solution. These solutions take time and should be carefully considered.