CVE-2025-24900: Concorde CSRF vulnerability due to insecure configuration of authentication cookie attributes
Description
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.
Classification
CVE ID: CVE-2025-24900
CVSS Base Severity: HIGH
CVSS Base Score: 8.6
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Affected Products
Vendor: nexryai
Product: concorde
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.05% (probability of being exploited)
EPSS Percentile: 18.37% (scored less or equal to compared to others)
EPSS Date: 2025-03-12 (when was this score calculated)
References
https://github.com/nexryai/concorde/security/advisories/GHSA-5hgq-9vw8-7v87https://github.com/nexryai/concorde/commit/2309b4a292828ddba4d57cf0e914bc433095871d
https://github.com/nexryai/concorde/commit/f3f54bde6a37ad310f83ae46de54a286c4b74059