Identifying Vulnerabilities in AWS Cloud Security for CDK Users
AWS has alerted users of its Cloud Development Kit (CDK) to vulnerabilities in cloud security that could lead to complete account takeover. Discovered by Aqua on June 27, this flaw can allow attackers to perform name-squatting on AWS S3 staging buckets, crucial for cloud application deployments. The issue affects CDK versions v2.148.1 and earlier, impacting about 1% of users.
Understanding S3 Bucket Name-Squatting
For effective deployment, organizations use the CDK, an open-source framework, to manage infrastructure as code (IaC). Users must bootstrap their environment to prepare for deployments, creating essential infrastructure components including an S3 staging bucket. However, AWS defaults the bucket naming pattern, creating predictability for attackers.
The Attack Scenario
- An attacker can guess the CDK staging bucket name if they have access to the AWS Account ID and Region.
- Creating a bucket with this name blocks the actual user from deployment, leading to a denial of service (DoS).
- In cases where the CDK reads and writes data, this can escalate to a full account takeover.
Mitigating the Risks
AWS has updated its documentation to highlight the need for customizing bootstrap resources. Users are advised to change the default 'qualifier' in CDK bootstrap to prevent such vulnerabilities. Additionally, fixes in CDK version v2.149.0 prevent pushing data to unauthorized buckets, although older versions remain susceptible.
This article was prepared using information from open sources in accordance with the principles of Ethical Policy. The editorial team is not responsible for absolute accuracy, as it relies on data from the sources referenced.