Concorde, formerly know as Nexkey, is a fork of the federated microblogging platform Misskey. Due to a lack of CSRF countermeasures and improper settings of cookies for MediaProxy authentication, there is a vulnerability that allows MediaProxy authentication to be bypassed. In versions prior to 12.25Q1.1, the authentication cookie does not have the SameSite attribute. This allows an attacker to bypass MediaProxy authentication and load any image without restrictions under certain circumstances. In versions prior to 12.24Q2.3, this cookie was also used to authenticate the job queue management page (bull-board), so bull-board authentication is also bypassed. This may enable attacks that have a significant impact on availability and integrity.
The affected versions are too old to be covered by this advisory, but the maintainers of Concorde strongly recommend not using older versions. Version 12.25Q1.1 contains a patch. There is no effective workaround other than updating.

AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CWE-352

https://github.com/nexryai/concorde/commit/2309b4a292828ddba4d57cf0e914bc433095871d

https://github.com/nexryai/concorde/commit/f3f54bde6a37ad310f83ae46de54a286c4b74059

https://github.com/nexryai/concorde/security/advisories/GHSA-5hgq-9vw8-7v87