#VU72011 Arbitrary file upload in Zulip Server

Published: 2023-02-07

Vulnerability identifier: #VU72011

Vulnerability risk: Medium


CVE-ID: CVE-2023-22735


Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Zulip Server
Web applications / Other software

Vendor: Zulip


The vulnerability allows a remote user to perform XSS attacks.

The vulnerability exists due to application allows to upload files with arbitrary Content-Type. Such file will be served from the Zulip hostname with Content-Disposition: inline and no Content-Security-Policy header. A remote user can upload a malicious file and execute arbitrary Javascript in the victim's browser in security context of the website.


Install updates from vendor's website.

The vulnerability affects the main branch between 2023-01-09 and 2023-02-07.

Vulnerable software versions

Zulip Server: 6.1


External links

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

Latest bulletins with this vulnerability