How should we interpret CVSS severity scores?

CVSS estimates technical severity, but it does not automatically equal business risk. Prioritize using context like internet exposure, asset criticality, known exploitation, and whether compensating controls exist. A Medium CVSS on an exposed production system can be more urgent than a Critical on an isolated non-production host.

Vulnerability Database

Q: What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

Q: What's the difference between a vulnerability, an exploit, and a zero-day?

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. Risk increases sharply when exploitation becomes reliable or widespread.

Q: Why do vulnerabilities keep reappearing in our environment?

Recurring findings usually come from incomplete asset discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host.

Q: How do we prioritize remediation without burning out the team?

Use a repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress so remediation is steady, not reactive.

Q: How can SynScan help reduce vulnerability risk over time?

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.

362,750

Total vulnerabilities in the database

aws-cdk-lib has Insertion of Sensitive Information into Log File vulnerability when using Cognito UserPoolClient Construct — aws-cdk-lib

Summary

The AWS Cloud Development Kit (CDK) is an open-source framework for defining cloud infrastructure using code. Customers use it to create their own applications which are converted to AWS CloudFormation templates during deployment to a customer’s AWS account. CDK contains pre-built components called "constructs" that are higher-level abstractions providing defaults and best practices. This approach enables developers to use familiar programming languages to define complex cloud infrastructure more efficiently than writing raw CloudFormation templates.

The CDK Cognito UserPool construct deploys an AWS cognito user pool. An Amazon Cognito user pool is a user directory for web and mobile app authentication and authorization. Customers can deploy a client under this user pool through construct ‘UserPoolClient’ or through helper method 'addClient'. A user pool client resource represents an Amazon Cognito user pool client which is a configuration within a user pool that interacts with one mobile or web application authenticating with Amazon Cognito.

When users of the 'cognito.UserPoolClient' construct generate a secret value for the application client in AWS CDK, they can then reference the generated secrets in their stack. The CDK had an issue where, when the custom resource performed an SDK API call to 'DescribeCognitoUserPoolClient' to retrieve the generated secret, the full response was logged in the associated lambda function's log group. Any user authenticated in the account where logs of the custom resource are accessible and who has read-only permission could view the secret written to those logs.

This issue does not affect customers who are generating the secret value outside of the CDK as the secret is not referenced or logged.

Impact

To leverage this issue, an actor has to be authenticated in the account where logs of the custom resource Custom::DescribeCognitoUserPoolClient are accessible and have read-only permission for lambda function logs.

Users can review access to their log group through AWS CloudTrail logs to detect any unexpected access to read the logs.

Impacted versions: >2.37.0 and <=2.187.0

Patches

The patches are included in the AWS CDK Library release v2.187.0. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes. To fully address this issue, users should rotate the secret by generating a new secret stored in AWS Secrets Manager. References to the secret will use the new secret on update.

When new CDK applications using the latest version are initialized, they will use the new behavior with updated logging.

Existing applications must upgrade to the latest version, change the feature flag (@aws-cdk/cognito:logUserPoolClientSecretValue) to false, redeploy the application to apply this fix and use the new implementation with updated logging behavior.

Workarounds

Users can override the implementation changing Logging to be Logging.withDataHidden(). For example define class CustomUserPoolClient extends UserPoolClient and in the new class define get userPoolClientSecret() to use Logging.withDataHidden().

Example

export class CustomUserPoolClient extends UserPoolClient {

  private readonly customUserPool : UserPool;
  private readonly customuserPoolClientId : string;
  constructor(scope: Construct, id: string, props: UserPoolClientProps) {
    super(scope, id, props);

    this.customUserPool = new UserPool(this, &#039;pool&#039;, {
      removalPolicy: RemovalPolicy.DESTROY,
    });

    const client = this.customUserPool.addClient(&#039;client&#039;, { generateSecret: true });
  }



  // Override the userPoolClientSecret getter to always return the secret
  public get userPoolClientSecret(): SecretValue {
    // Create the Custom Resource that assists in resolving the User Pool Client secret
    const secretValue = SecretValue.resourceAttribute(new AwsCustomResource(
      this,
      &#039;DescribeCognitoUserPoolClient&#039;,
      {
    resourceType: &#039;Custom::DescribeCognitoUserPoolClient&#039;,
    onUpdate: {
      region: cdk.Stack.of(this).region,
      service: &#039;CognitoIdentityServiceProvider&#039;,
      action: &#039;describeUserPoolClient&#039;,
      parameters: {
        UserPoolId: this.customUserPool.userPoolId,
        ClientId: this.customUserPool,
      },
      physicalResourceId: PhysicalResourceId.of(this.userPoolClientId),
      // Disable logging of sensitive data
      logging: Logging.withDataHidden(),
    },
    policy: AwsCustomResourcePolicy.fromSdkCalls({
      resources: [this.customUserPool.userPoolArn],
    }),
    installLatestAwsSdk: false,
      },
    ).getResponseField(&#039;UserPoolClient.ClientSecret&#039;));
    
    return secretValue;
  }
}

References

If you have any questions or comments about this advisory please contact AWS/Amazon Security via our vulnerability reporting page or directly via email to [email protected]. Please do not create a public GitHub issue.

Published: Mar 31, 2025
Updated: Apr 30, 2025
GHSA: GHSA-qq4x-c6h6-rfxh
Severity: Medium
Exploit:
CISA KEV:

CVSS v3:

Severity: Medium
Score: 6.5
AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

No CWE or OWASP classifications available.

Affected Software
References

Software	From	Fixed in
aws-cdk-lib	2.37.0	2.187.0

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Frequently Asked Questions

What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.