CVE-2021-43807

Name: CVE-2021-43807
Creator: NVD / NIST
Published: 2021-12-14T18:15:08.573+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 1.42%

Last modified Jun 17, 2026

CVE-2021-43807 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Opencast is an Open Source Lecture Capture & Video Management for Education. Opencast versions prior to 9.10 allow HTTP method spoofing, allowing to change the assumed HTTP method via URL parameter. EPSS estimates a 1.42% chance of exploitation in the next 30 days.

Description

Opencast is an Open Source Lecture Capture & Video Management for Education. Opencast versions prior to 9.10 allow HTTP method spoofing, allowing to change the assumed HTTP method via URL parameter. This allows attackers to turn HTTP GET requests into PUT requests or an HTTP form to send DELETE requests. This bypasses restrictions otherwise put on these types of requests and aids in cross-site request forgery (CSRF) attacks, which would otherwise not be possible. The vulnerability allows attackers to craft links or forms which may change the server state. This issue is fixed in Opencast 9.10 and 10.0. You can mitigate the problem by setting the `SameSite=Strict` attribute for your cookies. If this is a viable option for you depends on your integrations. We strongly recommend updating in any case.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

1.42%

69.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-290

Affected Software

Vendor	Product	Versions
Apereo	Opencast	< 9.10

References

https://github.com/opencast/opencast/commit/59cb6731067283e54f15462be38b6117d8b9ea8b#diff-9c5fb3d1b7e3b0f54bc5c4182965c4fe1f9023d449017cece3005d3f90e8e4d8Patch, Third Party Advisory
https://github.com/opencast/opencast/commit/8f8271e1085f6f8e306c689d6a56b0bb8d076444Patch, Third Party Advisory
https://github.com/opencast/opencast/security/advisories/GHSA-j4mm-7pj3-jf7vExploit, Patch, Third Party Advisory
https://github.com/opencast/opencast/commit/59cb6731067283e54f15462be38b6117d8b9ea8b#diff-9c5fb3d1b7e3b0f54bc5c4182965c4fe1f9023d449017cece3005d3f90e8e4d8Patch, Third Party Advisory
https://github.com/opencast/opencast/commit/8f8271e1085f6f8e306c689d6a56b0bb8d076444Patch, Third Party Advisory
https://github.com/opencast/opencast/security/advisories/GHSA-j4mm-7pj3-jf7vExploit, Patch, Third Party Advisory

Timeline

Published: Dec 14, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-43807?

How severe is CVE-2021-43807?

CVE-2021-43807 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 1.42% probability of exploitation in the next 30 days.

How do I fix CVE-2021-43807?

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-2021-43807?

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

Scan your code now

Source: NVD / NIST