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

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

!privatefield

!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.

js 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

js 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;