HTTP Method Spoofing

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2021-43807: 1.46% estimated exploitation activity in the next 30 days; percentile 73.65 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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. Impact The vulnerability allows attackers to craft links or forms which may change the server state. For example, the following GET request would create a new user: If an admin is logged in to legacy.opencast.org and accidentally clicks this link, a user will silently be created. Patches This issue is fixed in Opencast 9.10 and 10.0. Workarounds 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. References - Fix for 10.0 - Fix for 9.10 For more information…

Published by the source

14 Dec 2021, 21:43 UTC

Last modified by the source

1 Feb 2023, 05:06 UTC

Source last checked

26 Oct 2026, 16:07 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-j4mm-7pj3-jf7v

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# Patch Next advisory brief: CVE-2021-43807

Advisory: HTTP Method Spoofing
IDs: CVE-2021-43807, GHSA-j4mm-7pj3-jf7v
Record: https://patchnext.com/advisories/cve-2021-43807 (revision 1, source checked 26 Oct 2026, 16:07 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.opencastproject:opencast-common 9.10. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.opencastproject:opencast-common: affected < 9.10; fixed in 9.10

## Suggested inspection (read-only)
- Maven org.opencastproject:opencast-common: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.opencastproject:opencast-common.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-j4mm-7pj3-jf7v (GitHub-reviewed advisory GHSA-j4mm-7pj3-jf7v lists affected ranges: Maven org.opencastproject:opencast-common >=0 <9.10)

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