Jmix is a set of libraries and tools to speed up Spring Boot data-centric application development. In versions 1.0.0 to 1.6.1 and 2.0.0 to 2.3.4, the input parameter, which consists of a file path and name, can be manipulated to return the Content-Type header with text/html if the name part ends with .html. This could allow malicious JavaScript code to be executed in the browser. For a successful attack, a malicious file needs to be uploaded beforehand. This issue has been patched in versions 1.6.2 and 2.4.0. A workaround is provided on the Jmix documentation website.

Affected: Maven: io.jmix.rest:jmix-rest

### Impact

The input parameter, which consists of a file path and name, can be manipulated to return the Content-Type header with text/html if the name part ends with .html. This could allow malicious JavaScript code to be executed in the browser. For a successful attack, a malicious file needs to be uploaded beforehand.

The severity of the vulnerability is mitigated by the fact that the application UI and the generic REST API are typically accessible only to authenticated users. Additionally, the /files endpoint in Jmix requires specific permissions and is disabled by default.

### Patches

The problem has been fixed in Jmix 1.6.2+ and 2.4.0+.

### Workarounds

A workaround for those who are unable to upgrade: [Disable Files Endpoint in Jmix Application](https://docs.jmix.io/jmix/files-vulnerabilities.html#disable-files-endpoint-in-jmix-application).