CVE-2021-41263

Secure/signed cookies share secrets between sites in rails_multisite

Description

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.

Categories

8.3
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.20%
Third-Party Advisory github.com Third-Party Advisory github.com
Affected: discourse rails_multisite
Published at:
Updated at:

References

Link Tags
https://github.com/discourse/rails_multisite/security/advisories/GHSA-844m-cpr9-jcmh third party advisory
https://github.com/discourse/rails_multisite/commit/c6785cdb5c9277dd2c5ac8d55180dd1ece440ed0 third party advisory patch

Frequently Asked Questions

What is the severity of CVE-2021-41263?
CVE-2021-41263 has been scored as a high severity vulnerability.
How to fix CVE-2021-41263?
To fix CVE-2021-41263, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-41263 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-41263 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-41263?
CVE-2021-41263 affects discourse rails_multisite.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.