---
cve: "CVE-2021-41263"
severity: "HIGH"
cvss: 8.3
epss: "61%"
vendor: "discourse"
kev: false
exploited: false
published: "2021-11-15 20:15:20"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-15T17:34:17+02:00"
---

# CVE-2021-41263

> 8.3 HIGH · 🧪 PoC

## Beschreibung

rails_multisite provides multi-db support for Rails applications. In affected versions this vulnerability impacts any Rails applications using `rails_multisite` alongside Rails' signed/encrypted cookies. Depending on how the application makes use of these cookies, it may be possible for an attacker to re-use cookies on different 'sites' within a multi-site Rails application. The issue has been patched in v4 of the `rails_multisite` gem. Note that this upgrade will invalidate all previous signed/encrypted cookies. The impact of this invalidation will vary based on the application architecture.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Gering | warn |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- c6785cdb5c9277dd2c5ac8d55180dd1ece440ed0 (Commit)

## Referenzen

- <https://github.com/discourse/rails_multisite/security/advisories/GHSA-844m-cpr9-jcmh>
- <https://github.com/discourse/rails_multisite/commit/c6785cdb5c9277dd2c5ac8d55180dd1ece440ed0>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2021-41263) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_