How to prevent committing secrets in code

detect-secrets

Committing passwords, SSH keys and API keys to your code repositories is quite common. This doesn’t make it less dangerous. Yes, if you are ‘moving fast and breaking things’, it is sometimes easier to take shortcuts to simplify development and testing. But these broken things will eventually have to be fixed, as security of your product and perhaps even company, is at risk. Fixing things later in the development cycle is likely be more complicated and costly.

I’m not trying to scaremonger, there are already plenty of news articles about data breaches wiping out value for companies. My point is merely about the fact that it is much easier to address things early in the development, rather than waiting for a pentest or, worse still, a malicious attacker to discover these vulnerabilities.

Disciplined engineering and teaching your staff secure software development are certainly great ways to tackle this. There has to, however, be a fallback mechanism to detect (and prevent) mistakes. Thankfully, there are a number of open-source tools that can help you with that:

You will have to assess your own environment to pick the right tool that suits your organisation best.

If you read my previous blogs on integrating application testing and detecting vulnerable dependencies, you know I’m a big fan of embedding such tests in your Continuous Integration and Continuous Deployment (CI/CD) pipeline. This provides instant feedback to your development team and minimises the window between discovering and fixing a vulnerability. If done right, the weakness (a secret in the code repository in this case) will not even reach the production environment, as it will be caught before the code is committed. An example is on the screenshot at the top of the page.

For this reason (and a few others), the tool that I particularly like is detect-secrets, developed in Python and kindly open-sourced by Yelp. They describe the reasons for building it and explain the architecture in their blog. It’s lightweight, language agnostic and integrates well in the development workflow. It relies on pre-commit hooks and will not scan the whole repository – only the chunk of code you are committing.

Yelp’s detect-secrets, however, has its limitations. It needs to be installed locally by engineers which might be tricky with different operating systems. If you do want to use it but don’t want to be restricted by local installation, it can also run out of a container, which can be quite handy.


How to integrate application security testing in the CI/CD pipeline

ZAP.png

In this blog I’m going to build on my previous posts on agile security, DevSecOps culture and managing vulnerabilities in open source libraries to talk about automating application security testing.

Read the rest of this entry »


Agile security. Part 2: User stories

Clickup

In the previous blog, I wrote about how you as a security specialist can succeed in the world of agile development, where the requirements are less clear, environment more fluid and change is celebrated not resisted.

Adjusting your mindset and embracing the fact that there will be plenty of unknowns is the first step in adopting agile security practices. You can still influence the direction of the product development to make it more resilient, safe and secure by working with the Product Owner and contributing your requirements to the product backlog.

Simply put, product backlog is a list of desired functionality, bug fixes and other requirements needed to deliver a viable product. There are plethora of tools out there to help manage dependencies and prioritisation to make the product owner’s job easier. The image at the top of this post is an example of one of such tools and you can see some example requirements there.

As a security specialist, you can communicate your needs in a form of user stories or help contribute to existing ones, detailing security considerations. For example, ”Customer personal data should be stored securely” or “Secure communication channels should be used when transmitting sensitive information”. Below are a couple more examples from different categories.

Ticket 2Ticket 1

When writing security user stories, you should try and elaborate as much as possible on the problem you are trying to solve, what value it will provide if solved and the acceptance criteria. Each story will then have points assigned which signifies how much effort a particular functionality will require. The process of arriving to the final number is quite democratic and usually involves playing planning (sometimes also called Scrum) poker in which every developer will estimate how long each story is going to take with some discussion and eventual consensus. You can do it with an app as on the image below, or the old school way with a deck of cards. 

Scrum poker

You don’t have to use the above number pattern, and opt-in instead for the Fibonacci sequence or T-shirt sizes.

It’s important that the security team is involved in sprint planning to contribute to the estimates and help the product owner with prioritisation. Other Scrum meetings, like backlog refinement and daily stand-ups are also worthwhile to attend to be able clarify your requirements (including value, risk, due dates and dependencies) and help remove security related impediments.

A culture of collaboration between teams is essential for the DevSecOps approach to be effective. Treating security as not something to workaround but as a value adding product feature is the mindset product and engineering teams should adopt. However, it’s up to security specialists to recognise the wider context in which they operate and accept the fact that security is just one of the requirements the team needs to consider. If the business can’t generate revenue because crucial features that customers demand are missing, it’s little consolation that security vulnerabilities have been addressed. After all, it’s great to have a secure product, but less so when nobody uses it.


How to manage vulnerabilities in your open source packages. Part 2: Integrating Snyk in your CI/CD pipeline

We learnt how to detect vulnerable packages in your projects using Snyk in the previous blog. Here, in the true DevSecOps fashion, I would like outline how to integrate this tool in your CI/CD pipeline.

Although the approach described in the previous blog has its merits, it lacks proactivity, which means you might end up introducing outdated packages in your codebase. To address this limitation, I’m going to describe how to make Snyk checks part of your deployment workflow. I’ll be using CircleCI here as an example, but the principles can be applied using any CI tool.

A step-by-step guidance on configuring the integration is available on both the Snyk and CircleCI websites. In the nutshell, it’s just about adding the Snyk Orb and API to CircleCI.

After the initial set-up, an additional test will be added to your CircleCI workflow.

Pipeline

If vulnerabilities are identified, you can set CircleCI to either fail the build to prevent outdated libraries to be introduced or let the build complete and flag.

snyk_scan

Both methods have their pros and cons and will depend on the nature of your environment and risk appetite. It’s tempting to force the build fail to prevent more vulnerable dependencies being introduced but I suggest doing so only after checking with your developers and remediating existing issues in your repositories using the method described in the previous blog.

Tests

Snyk’s free version allows you only a limited number of scans per month, so you need to also weigh costs agains benefits when deploying this tool in your development, staging and production environments.

This approach will allow you to automate security tests in a developer-friendly fashion and hopefully bring development and security teams closer together, so the DevSecOps can be practiced.


How to manage vulnerabilities in your open source packages. Part 1: Using Snyk

We rely on open source libraries when we write code because it saves a lot of time (modern applications rely on hundreds of them), but these dependencies can also introduce vulnerabilities that are tricky to manage and easy to exploit by attackers.

One way of addressing this challenge is to check the open source packages you use for known vulnerabilities.

In this blog I would like to discuss how to do this using an open source tool called Snyk

Snyk

The first thing you want to do after creating an account is to integrate Snyk with your development environment. It supports a fair amount of systems, but here I would like to talk about GitHub as an example. The process of getting the rest of the integrations are pretty similar.

Snyk’s browser version has an intuitive interface and all you need to do is go to the Integrations tab, select GitHub and follow the instructions.

After granting the necessary permissions and selecting the code repositories you want tested (don’t forget the private ones too), they will be immediately scanned.

You will be able to see the results in the Projects tab with issues conveniently ordered by severity so you can easily prioritise what to tackle first. You can also see the dependency tree there which can be quite handy.

Project.png

A detailed description of the vulnerability and some recommendations on how to remediate it are also provided.

Most vulnerabilities can be fixed through either an upgrade or a patch and that’s what you should really do, or ask someone (perhaps by creating a ticket) if you don’t own the codebase. Make sure you test it first though as you don’t want the update to break your application.

Some fancy reporting (and checking license compliance) is only available in the paid plan but the basic version does a decent job too.

You can set up periodic tests with desired frequency (daily or weekly) which technically counts as continuous monitoring but it’s only the second best option compared to performing tests in your deployment pipeline. Integrating Snyk in your CI/CD workflow allows to prevent issues in your code before it even gets deployed. This is especially useful in organisations where code gets deployed multiple times a day with new (potentially vulnerable) libraries being introduced. And that’s something we are going to discuss in my next blog.


AWS security fundamentals: IAM

IAM

Here I am going to build on my previous blog of inventorying AWS accounts and talk about identity and access management. By now you have probably realised that your organisation, depending on its size, has more accounts with a lot of associated resources than you initially thought. The way users are created and access is managed in these accounts has a direct impact on the overall security of your infrastructure.

What accounts should your company have? Well it really depends on the nature of your organisation but I tend to see the following pattern for software development driven companies:

1. Organisation root. Your organisation root account should be used to create other accounts (and some other limited amount of operations) and otherwise shouldn’t be touched. Secure the credentials and leave it alone. It should not have any resources associated with it.

2. Identity. Not strictly necessary to have a separate account for this but isn’t it great to be able to manage all your users in a single account?

3. Operations. This account should be used for log collection and analysis. Your security team will be happy.

4, 5 and 6. A separate account for your development, staging and production environments. It’s a good idea to separate them for the ease of managing permissions and pleasing auditors.

Users and services that are managed within an AWS account, should only get access to what they need.

Security specialists are spending a great deal of their time reviewing firewall rules when working on their on-premise infrastructure to ensure they are not too permissive. When we move to the cloud, these rules look somewhat different but their importance has only increased.

To demonstrate the relationship between accounts, users, groups, roles and permissions, let’s walk through an example scenario of a developer in your company requiring read only access to the staging environment.

No automation or anything even remotely advanced is going to be discussed here as we are just covering the basics in this blog. It is no less important, however, to get these right. The principles discussed here will lay the foundation for more advanced concepts. Again, the terminology here is specific to AWS but overarching principles can be applied to any cloud environment.

To start with this scenario, let’s create a custom role CompanyReadOnly and attach an AWS managed ReadOnlyAccess policy in the Permissions tab.

Role Policies
CompanyReadOnly ReadOnlyAccess

This role allows a trusted entity (an account in this case) to access this account. When you access this account you will get the permissions defined in the policy.

Let’s say we have an account where all users are managed (the Identity account in point 2 in the list above). In this account, create a custom policy CompanyAssumeRoleStagingReadOnly allowing assuming the right role, where 123456789012 is Staging account ID which is the trusted entity for the Identity account:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": "sts:AssumeRole",
            "Resource": "arn:aws:iam::123456789012:role/CompanyReadOnly"
        }
    ]
}

Now let’s create a custom StagingReadOnly group and attach the above policy in the Permission tab.

Group Permissions
StagingReadOnly CompanyAssumeRoleStagingReadOnly

Finally add a user to that group:

User Group Permissions
Developer StagingReadOnly CompanyAssumeRoleStagingReadOnly

In this group additional permissions can be added, e.g. AWS managed enforce-mfa policy for mandatory multi-factor authentication.

Of course, granular policies specifying access to particular services rather than blanket ReadOnly is preferred. Remember the aim here is to demonstrate IAM fundamental principles rather than recommend specific approaches you should use. The policies will depend on the AWS resources your organisation actually uses.


Learn software engineering

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I’ve recently decided to brush up on my programming skills with one of the courses on Udemy. Despite completing a degree in Computer Science back in the day, my recent focus has been away from software development and a lot has changed since I graduated.

At university I studied mathematics and algorithms but actual programming was performed on archaic languages – such as Pascal for high-level and Assembly for low-level programming.

Although they provide a solid foundation, I was looking for something more practical and because of this I ended up taking up Python because of its versatility. Python is not only widely used, but can also be applied to a variety of projects, including data analysis and machine learning.

The course has been very good and Jupyter notebooks with extensive comments and exercises are available for free on GitHub.

You can start applying it in practice straight away or just have some fun with your own pet projects.

If you’re an experienced developer or just want to have some extra practice, I found the below brain teasers quite entertaining:

On the other hand, if you are just starting up and would like some more grounding in computer science, check out Harvard University’s CS50’s Introduction to Computer Science. It’s completely free, online and self-paced. It starts with some basic principles and lets you put them into practice straight away through Scratch, a graphical programming language developed by MIT.  You then go on to learn more advanced concepts and apply them using C, Python, JavaScript and more.

The course also has a great community, so I highly recommend checking it out.