CVE-2023-39345: Unauthorized Access to Private Fields in User Registration API

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.

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;