Navidrome is an open source web-based music collection server and streamer. Prior to version 0.60.0, a cross-site scripting vulnerability in the frontend allows a malicious attacker to inject code through the comment metadata of a song to exfiltrate user credentials. This issue has been patched in version 0.60.0.

Affected: Go: github.com/navidrome/navidrome

### Summary

An XSS vulnerability in the frontend allows a malicious attacker to inject code through the comment metadata of a song to exfiltrate user credentials.

An attacker's maliciously crafted song has to be added to Navidrome to exploit the vulnerability.

### Details

The frontend is using React. In various places, the code uses the `dangerouslySetInnerHTML` escape hatch to set the content of an HTML element.

In some places, the value is first sanitized by removing anything looking like an HTML tag. In at least one place the value is used as is, thus leading to the XSS vulnerability.

In `MultiLineTextField` component, the input is split into lines and rendered through the `dangerouslySetInnerHTML` property.

```js <div data-testid={`${source}.${idx}`} key={md5(line + idx)} dangerouslySetInnerHTML={{ __html: line }} /> ```

This component is then used in the `SongInfo` and `AlbumInfo` components, when rendering the comment of the song or album. The contents of the comments field is taken verbatim from the metadata of a song, such as the VORBIS `COMMENT` comment of a FLAC file.

By crafting the contents of the comment field, an attacker can inject code into the frontend, which runs whenever a user views the song or album info.

Additionally, as the Navidrome API token is kept in local storage and since there's no CSP in place unless the user's configured one outside of Navidrome, the attacker can exfiltrate the API token.

### PoC

1. Modify the comment field…