In github.com/pion/webrtc, failed DTLS certificate verification doesn't stop data channel communication

Exploitation

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

CVSS

5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS

• CVE-2021-28681: 0.68% estimated exploitation activity in the next 30 days; percentile 52.32 (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.

Impact Data channel communication was incorrectly allowed with users who have failed DTLS certificate verification. This attack requires Attacker knows the ICE password. Only take place during PeerConnection handshake. This attack can be detected by monitoring PeerConnectionState in all versions of Pion WebRTC. Patches Users should upgrade to v3.0.15. The exact patch is https://github.com/pion/webrtc/commit/545613dcdeb5dedb01cce94175f40bcbe045df2e Workarounds Users should listen for when PeerConnectionState changes to PeerConnectionStateFailed. When it enters this state users should not continue using the PeerConnection. For more information If you have any questions or comments about this advisory: Open an issue in https://github.com/pion/webrtc Email us at team@pion.ly Thank you to https://github.com/Gaukas for discovering this.

Published by the source

25 May 2021, 18:42 UTC

Last modified by the source

29 Aug 2023, 23:21 UTC

Source last checked

26 Oct 2026, 14:58 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-74xm-qj29-cq8p

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# Patch Next advisory brief: CVE-2021-28681

Advisory: In github.com/pion/webrtc, failed DTLS certificate verification doesn't stop data channel communication
IDs: CVE-2021-28681, GHSA-74xm-qj29-cq8p
Record: https://patchnext.com/advisories/cve-2021-28681 (revision 1, source checked 26 Oct 2026, 14:58 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/pion/webrtc/v3 3.0.15. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/pion/webrtc/v3: affected < 3.0.15; fixed in 3.0.15

## Suggested inspection (read-only)
- Go github.com/pion/webrtc/v3: 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 github.com/pion/webrtc/v3.
- 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-74xm-qj29-cq8p (GitHub-reviewed advisory GHSA-74xm-qj29-cq8p lists affected ranges: Go github.com/pion/webrtc/v3 >=0 <3.0.15)

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