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Unauthorized Access to Private Fields in User Registration API

High severity GitHub Reviewed Published Nov 3, 2023 in strapi/strapi • Updated Nov 6, 2023

Package

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

Affected versions

>= 4.0.0, < 4.13.1

Patched versions

4.13.1
npm @strapi/strapi (npm)
>= 4.0.0, < 4.13.1
4.13.1

Description

System Details

Name Value
OS Windows 11
Version 4.11.1 (node v16.14.2)
Database mysql

Description

I marked some fields as private fields in user content-type, and tried to register as a new user via api, at the same time I added content to fill the private fields and sent a post request, and as you can see from the images below, I can write to the private fields.

register

user

private_field

table

To prevent this, I went to the extension area and tried to extend the register method, for this I wanted to do it using the sanitizeInput function that I know in the source codes of the strap. But the sanitizeInput function did not filter out private fields.

  const { auth } = ctx.state;
  const data = ctx.request.body;
  const userSchema = strapi.getModel("plugin::users-permissions.user");

  sanitize.contentAPI.input(data, userSchema, { auth });

here's the solution I've temporarily kept to myself, code snippet

  const body = ctx.request.body;

  const { attributes } = strapi.getModel("plugin::users-permissions.user");

  const sanitizedData = _.omitBy(body, (data, key) => {
    const attribute = attributes[key];

    if (_.isNil(attribute)) {
      return false;
    }

    //? If you want, you can throw an error for fields that we did not expect.

    // if (_.isNil(attribute))
    //   throw new ApplicationError(`Unexpected value ${key}`);

    // if private value is true, we do not want to send it to the database.
    return attribute.private;
  });

  return sanitizedData;

References

@alexandrebodin alexandrebodin published to strapi/strapi Nov 3, 2023
Published to the GitHub Advisory Database Nov 3, 2023
Reviewed Nov 3, 2023
Published by the National Vulnerability Database Nov 6, 2023
Last updated Nov 6, 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
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
High
Availability
Low

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:A/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L

EPSS score

0.068%
(32nd percentile)

Weaknesses

CVE ID

CVE-2023-39345

GHSA ID

GHSA-gc7p-j5xm-xxh2

Source code

Credits

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