CVE-2021-3509

Name: CVE-2021-3509
Creator: NVD / NIST
Published: 2021-05-27T00:15:08.577+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 1.70%

Last modified Jun 17, 2026

CVE-2021-3509 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. A flaw was found in Red Hat Ceph Storage 4, in the Dashboard component. In response to CVE-2020-27839, the JWT token was moved from localStorage to an httpOnly cookie. EPSS estimates a 1.70% chance of exploitation in the next 30 days.

Description

A flaw was found in Red Hat Ceph Storage 4, in the Dashboard component. In response to CVE-2020-27839, the JWT token was moved from localStorage to an httpOnly cookie. However, token cookies are used in the body of the HTTP response for the documentation, which again makes it available to XSS.The greatest threat to the system is for confidentiality, integrity, and availability.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

1.70%

74.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Redhat	Ceph Storage	4.0

References

https://bugzilla.redhat.com/show_bug.cgi?id=1950116Issue Tracking, Patch, Vendor Advisory
https://github.com/ceph/ceph/blob/f1557e8f62d31883d3d34ae241a1a26af11d923f/src/pybind/mgr/dashboard/controllers/docs.py#L394-L409Exploit, Third Party Advisory
https://github.com/ceph/ceph/commit/7a1ca8d372da3b6a4fc3d221a0e5f72d1d61c27bPatch, Third Party Advisory
https://github.com/ceph/ceph/commit/adda853e64bdba1288d46bc7d462d23d8f2f10caPatch, Third Party Advisory
https://github.com/ceph/ceph/commit/af3fffab3b0f13057134d96e5d481e400d8bfd27Patch, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1950116Issue Tracking, Patch, Vendor Advisory
https://github.com/ceph/ceph/blob/f1557e8f62d31883d3d34ae241a1a26af11d923f/src/pybind/mgr/dashboard/controllers/docs.py#L394-L409Exploit, Third Party Advisory
https://github.com/ceph/ceph/commit/7a1ca8d372da3b6a4fc3d221a0e5f72d1d61c27bPatch, Third Party Advisory
https://github.com/ceph/ceph/commit/adda853e64bdba1288d46bc7d462d23d8f2f10caPatch, Third Party Advisory
https://github.com/ceph/ceph/commit/af3fffab3b0f13057134d96e5d481e400d8bfd27Patch, Third Party Advisory

Timeline

Published: May 27, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-3509?

How severe is CVE-2021-3509?

CVE-2021-3509 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 1.70% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3509?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-3509?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST