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Authentication Bypass in @strapi/plugin-users-permissions

High severity GitHub Reviewed Published Apr 18, 2023 in strapi/strapi • Updated Apr 19, 2023

Package

npm @strapi/plugin-users-permissions (npm)

Affected versions

>= 3.2.1, < 4.6.0

Patched versions

4.6.0

Description

Summary

Strapi through 4.5.6 does not verify the access or ID tokens issued during the OAuth flow when the AWS Cognito login provider is used for authentication.

Details

Strapi through 4.5.6 does not verify the access or ID tokens issued during the OAuth flow when the AWS Cognito login provider is used for authentication. A remote attacker could forge an ID token that is signed using the 'None' type algorithm to bypass authentication and impersonate any user that use AWS Cognito for authentication.

IoC

Reviewing of application logs is recommended to detect any suspicious activity. Running the following regex pattern will extract all ID tokens sent to /api/auth/cognito/callback.

/\/api\/auth\/cognito\/callback\?[\s\S]*id_token=\s*([\S]*)/

Once you have a list of the ID tokens, you will need to verify each token using the public key file for your AWS Cognito user pool that you can download from https://cognito-idp.{region}.amazonaws.com/{userPoolId}/.well-known/jwks.json. If there are any JWT tokens that cannot be verified using the correct public key, then you need to inspect the JWT body and see if it contains the email and cognito:username claims (example below).

{
  "cognito:username": "auth-bypass-example",
  "email": "[email protected]"
}

If there are any JWTs that have this body, verify when the account with the email address was created. If the account was created earlier than the request to /api/auth/cognito/callback with the invalid JWT token, then you need to contact the user to inform them their account has been breached!

After upgrading to Strapi v4.6.0 or greater you will need to reconfigure your AWS Cognito provider to include the JWKS URL for it to work properly. If you do not reconfigure your provider you will receive an error message when attempting to login.

Impact

Any Strapi user using the users-permissions AWS Cognito provider before 4.6.0

References

@alexandrebodin alexandrebodin published to strapi/strapi Apr 18, 2023
Published to the GitHub Advisory Database Apr 18, 2023
Reviewed Apr 18, 2023
Last updated Apr 19, 2023

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Weaknesses

No CWEs

CVE ID

No known CVE

GHSA ID

GHSA-xv3q-jrmm-4fxv

Source code

Credits

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