An issue was discovered in Symfony 2.7.x before 2.7.50, 2.8.x before 2.8.49, 3.x before 3.4.20, 4.0.x before 4.0.15, 4.1.x before 4.1.9, and 4.2.x before 4.2.1. When using the scalar type hint `string` in a setter method (e.g. `setName(string $name)`) of a class that's the `data_class` of a form, and when a file upload is submitted to the corresponding field instead of a normal text input, then `UploadedFile::__toString()` is called which will then return and disclose the path of the uploaded file. If combined with a local file inclusion issue in certain circumstances this could escalate it to a Remote Code Execution.
http://www.securityfocus.com/bid/106249
https://lists.debian.org/debian-lts-announce/2019/03/msg00009.html
https://seclists.org/bugtraq/2019/May/21
https://symfony.com/blog/cve-2018-19789-disclosure-of-uploaded-files-full-path
Source: MITRE
Published: 2018-12-18
Updated: 2019-05-10
Type: CWE-434
Base Score: 5
Vector: AV:N/AC:L/Au:N/C:P/I:N/A:N
Impact Score: 2.9
Exploitability Score: 10
Severity: MEDIUM
Base Score: 5.3
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Impact Score: 1.4
Exploitability Score: 3.9
Severity: MEDIUM