AWS Security Blog

I am an AWS Professional Services consultant, which has me working directly with AWS customers on a daily basis. One of my customers recently asked me to provide a solution to help them fulfill their security requirements by having the flow log data from VPC Flow Logs sent to a central AWS account. This is a common requirement in some companies so that logs can be available for in-depth analysis. In addition, my customers regularly request a simple, scalable, and serverless solution that doesn’t require them to create and maintain custom code.

In this blog post, I demonstrate how to configure your AWS accounts to send flow log data from VPC Flow Logs to an Amazon S3 bucket located in a central AWS account by using only fully managed AWS services. The benefit of using fully managed services is that you can lower or even completely eliminate operational costs because AWS manages the resources and scales the resources automatically.

Solution overview

The solution in this post uses VPC Flow Logs, which is configured in a source account to send flow logs to an Amazon CloudWatch Logs log group. To receive the logs from multiple accounts, this solution uses a CloudWatch Logs destination in the central account. Finally, the solution utilizes fully managed Amazon Kinesis Firehose, which delivers streaming data to scalable and durable S3 object storage automatically without the need to write custom applications or manage resources. When the logs are processed and stored in an S3 bucket, these can be tiered into a lower cost, long-term storage solution (such as Amazon Glacier) automatically to help meet any company-specific or industry-specific requirements for data retention. (more…)

Today, we made available a new feature in AWS Artifact (our auditing and compliance portal) that enables you to review, accept, and track the status of your Business Associate Addendum (BAA). With this new feature, you can accept the terms of a BAA online, and instantly designate an AWS account as a “HIPAA Account” for use with protected health information (PHI) under the U.S. Health Insurance Portability and Accountability Act (HIPAA). In addition, you can sign in to AWS Artifact to confirm that your account is designated as a HIPAA Account, and review the terms of the BAA for that account. If you are no longer using a designated HIPAA Account in connection with PHI, you can remove that designation using the AWS Artifact interface.

Today’s release addresses two key customer needs in particular: (1) the need to enter into a BAA quickly, and (2) the need to easily track and control whether an AWS account is designated as a HIPAA Account under a BAA.

The BAA is the first specialized industry agreement that AWS is making available online. We chose to launch with the BAA as a commitment to AWS customer organizations who are reinventing the way healthcare is researched and delivered with the cloud. Many AWS customers have great stories to tell as we work together to use technology to advance the healthcare industry.

If you already have a BAA with AWS, or if you are considering designing or migrating a new solution that will create, receive, maintain, or transmit PHI on AWS, you can use AWS Artifact to manage your HIPAA Accounts today. As with all AWS Artifact features, there are no additional fees for using AWS Artifact to review, accept, and manage BAAs online.

– Chad

After you create your first AWS account, you might be tempted to start immediately addressing the issue that brought you to AWS. For example, you might set up your first website, spin up a virtual server, or create your first storage solution. However, AWS recommends that first, you follow some security best practices to help protect your AWS resources. In this blog post, I explain why you should follow AWS security best practices, and I link to additional resources so that you can learn more about each best practice.

Best practices to help secure your AWS resources

When you created an AWS account, you specified an email address and password you use to sign in to the AWS Management Console. When you sign in using these credentials, you are accessing the console by using your root account. Following security best practices can help prevent your root account from being compromised, which is an important safeguard because your root account has access to all services and resources in your account.

Create a strong password for your AWS resources

To help ensure that you protect your AWS resources, first set a strong password with a combination of letters, numbers, and special characters. For more information about password policies and strong passwords, see Setting an Account Password Policy for IAM Users. This also might be a good opportunity to use a third-party password management tool, which you can use to create and manage strong passwords. (more…)

Local Administrator Password Solution (LAPS) from Microsoft simplifies password management by allowing organizations to use Active Directory (AD) to store unique passwords for computers. Typically, an organization might reuse the same local administrator password across the computers in an AD domain. However, this approach represents a security risk because it can be exploited during lateral escalation attacks. LAPS solves this problem by creating unique, randomized passwords for the Administrator account on each computer and storing it encrypted in AD.

Deploying LAPS with AWS Microsoft AD requires the following steps:

1. Install the LAPS binaries on instances joined to your AWS Microsoft AD domain. The binaries add additional client-side extension (CSE) functionality to the Group Policy client.
2. Extend the AWS Microsoft AD schema. LAPS requires new AD attributes to store a password and its expiration time.
3. Configure AD permissions and delegate the ability to retrieve the local administrator password for IT staff in your organization.
4. Configure Group Policy on instances joined to your AWS Microsoft AD domain to enable LAPS. This configures the Group Policy client to process LAPS settings and uses the binaries installed in Step 1.

The following diagram illustrates the setup that I will be using throughout this post and the associated tasks to set up LAPS. Note that the AWS Directory Service directory is deployed across multiple Availability Zones, and monitoring automatically detects and replaces domain controllers that fail. (more…)

Starting today, you can create and search relationships across hierarchies in Amazon Cloud Directory by using typed links. With typed links, you can build directories that can be searched across hierarchies more efficiently by filtering your queries based on relationship type. Typed links also enable you to model different types of relationships between objects in different hierarchies and to use relationships to prevent objects from being deleted accidentally.

For more information about Cloud Directory typed links, see Cloud Directory Update – Support for Typed Links on the AWS Blog.

– Mahendra

Last month, we introduced policy summaries to make it easier for you to understand the permissions in your AWS Identity and Access Management (IAM) policies. On Thursday, May 25, I announced three new features that have been added to policy summaries and reviewed resource summaries. Yesterday, I reviewed the benefits of being able to view services and actions that are implicitly denied by a policy.

Today, I demonstrate how policy summaries make it easier for you to detect potential typos in your policies by showing you unrecognized services and actions. In this post, I show how this new feature can help you detect and fix potential typos in your policies.

Unrecognized services and actions

You can now use policy summaries to see unrecognized services and actions. One key benefit of this feature is that it helps you find possible typos in a policy. Let’s say your developer, Bob, creates a policy granting full List and Read permissions to some Amazon S3 buckets and full access to Amazon DynamoDB. Unfortunately, when testing the policy, Bob sees “Access denied” messages when he tries to use those services. To troubleshoot, Bob returns to the IAM console to review the policy summary. Bob sees that he inadvertently misspelled “DynamoDB” as “DynamoBD” (reversing the position of the last two letters) in the policy and notices that he does not have all of the list permissions for S3. (more…)

Last month, we introduced policy summaries to make it easier for you to understand the permissions in your AWS Identity and Access Management (IAM) policies. On Thursday, May 25, I announced three new features that have been added to policy summaries and reviewed one of those features: resource summaries. Tomorrow, I will discuss how policy summaries can help you find potential typos in your IAM policies.

Today, I describe how you can view the services and actions that are implicitly denied, which is the same as if the services or actions are not granted by an IAM policy. This feature allows you to see which actions are not included at each access level for a service that has limited access, which can help you pinpoint the actions that are necessary to grant Full: List and Read permissions to a specific service, for example. In this blog post, I cover two examples that show how you can use this feature to see which services and actions are not granted by a policy.

Show remaining services and actions

From the policy summary in the IAM console, you can now see the services and actions that are not granted by a policy by choosing the link next to the Allow heading (see the following screenshot). This enables you to view the remaining services or actions in a service with partial access, without having to go to the documentation.

Let’s look at the AWS managed policy for the Developer Power User. This policy grants access to 99 out 100 services, as shown in the following screenshot. You might want to view the remaining service to determine if you should grant access to it, or you might want to confirm that this policy does not grant access to IAM. To see which service is missing from the policy, I choose the Show remaining 1 link. (more…)

In March, we introduced policy summaries, which make it easier for you to understand the permissions in your AWS Identity and Access Management (IAM) policies. Today, we added three new features to policy summaries to improve the experience of understanding and troubleshooting your policies. First, we added resource summaries for you to see the resources defined in your policies. Second, you can now see which services and actions are implicitly denied by a policy. This allows you to see the remaining actions available for a service with limited access. Third, it is now easier for you to identify potential typos in your policies because you can now see which services and actions are unrecognized by IAM. Today, Tuesday, and Wednesday, I will demonstrate these three new features. In today’s post, I review resource summaries.

Resource summaries

Policy summaries now show you the resources defined in a policy. Previously, policy summaries displayed either All for all resources, the Amazon Resource Name (ARN) for one resource, or Multiple for multiple resources specified in the policy. Starting today, you can see the resource type, region, and account ID to summarize the list of resources defined for each action in a policy. Let’s review a policy summary that specifies multiple resources. (more…)

Today, the Resource Groups Tagging API introduced a pagination parameter to the GetResources action that makes it easier for you to manage lists of resources returned by your queries. Using this parameter, you can list your resources that are associated with specific tags or resource types, and limit result sets to a specific number per page. Previously, you could list resources only by the number of tags.

Let’s say you want to query your resources that have tags with the key of “stage” and the value of “production”. You want to return as many as 25 resources per page of results. The following Java code example meets those criteria.

TagFilter tagFilter = new TagFilter();
tagFilter.setKey("stage");
tagFilter.setValues(Arrays.asList(new String[] { "production" }));

List<TagFilter> tagFilters = new ArrayList<>();
tagFilters.add(tagFilter);

AWSResourceGroupsTaggingAPIClient client = new AWSResourceGroupsTaggingAPIClient();
GetResourcesRequest request = new GetResourcesRequest();
request.withResourcesPerPage(25).withTagFilters(tagFilters);
GetResourcesResult result = client.getResources(request);

Also, with the updated AWS CLI, the GetResources action by default returns all items that meet your query criteria.  If you want to use pagination, the AWS CLI continues to support the case in which you receive a subset of items returned from a query and a pagination token for looping through the remaining items.

For example, the following AWS CLI script uses automatic pagination to return all resources that meet the query criteria.

aws resourcegroupstaggingapi get-resources

However, if you want to return resources in groups of 25, the following AWS CLI script example uses custom pagination and returns as many as 25 resources per page that meet the query criteria.

aws resourcegroupstaggingapi get-resources –-resources-per-page 25

If you have comments about this post, submit them in the “Comments” section below. Start a new thread on the Resource Groups Tagging API forum if you have questions about or issues using the new functionality.

– Nitin

Securing data in transit is critical to the integrity of transactions on the Internet. Whether you log in to an account with your user name and password or give your credit card details to a retailer, you want your data protected as it travels across the Internet from place to place. One of the protocols in widespread use to protect data in transit is Transport Layer Security (TLS). Every time you access a URL that begins with “https” instead of just “http”, you are using a TLS-secured connection to a website.

To demonstrate that your application has a strong TLS configuration, you can use services like the one provided by SSL Labs. There are also open source, command-line-oriented TLS testing programs such as testssl.sh (which I do not cover in this post) and sslscan (which I cover later in this post). The goal of testing your TLS configuration is to provide evidence that weak cryptographic ciphers are disabled in your TLS configuration and only strong ciphers are enabled. In this blog post, I show you how to control the TLS security options for your secure load balancer in AWS CloudFormation, pass the TLS certificate and host name for your secure AWS Elastic Beanstalk application to the CloudFormation script as parameters, and then confirm that only strong TLS ciphers are enabled on the launched application by testing it with SSLLabs.

Background

In some situations, it’s not enough to simply turn on TLS with its default settings and call it done. Over the years, a number of vulnerabilities have been discovered in the TLS protocol itself with codenames such as CRIME, POODLE, and Logjam. Though some vulnerabilities were in specific implementations, such as OpenSSL, others were vulnerabilities in the Secure Sockets Layer (SSL) or TLS protocol itself. (more…)