# CVE-2021-28681: In github.com/pion/webrtc, failed DTLS certificate verification doesn't stop data channel communication

> Attackers can bypass DTLS certificate verification in Pion WebRTC by continuing to use a PeerConnection after verification failure, undermining secure communication guarantees.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Mar 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-74xm-qj29-cq8p, GO-2021-0104

## What is CVE-2021-28681?

CVE-2021-28681 is a medium-severity vulnerability in n/a, published on 18 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Pion WebRTC before 3.0.15 didn't properly tear down the DTLS Connection when certificate verification failed. The PeerConnectionState was set to failed, but a user could ignore that and continue to use the PeerConnection. )A WebRTC implementation shouldn't allow the user to continue if verification has failed.)

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2021-28681?

3 open source packages ship an affected version, including github.com/pion/webrtc/v3. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/pion/webrtc/v3` | Go | All versions | 3.0.15 |
| `github.com/pion/webrtc/v3` | Go | All versions | 3.0.15 |
| `github.com/pion/webrtc/v3` | Go | All versions | 3.0.15 |

Products: Webrtc Project Webrtc.

## How do I fix CVE-2021-28681?

Upgrade github.com/pion/webrtc/v3 to 3.0.15 or later.

## Is CVE-2021-28681 being exploited?

There is no known exploitation of CVE-2021-28681 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-28681 and fix it if it is affected.

What it is: CVE-2021-28681 is a medium-severity vulnerability in n/a, published on 18 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-28681 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/pion/webrtc/v3 (Go): affected all versions; fixed in 3.0.15
- github.com/pion/webrtc/v3 (Go): affected all versions; fixed in 3.0.15
- github.com/pion/webrtc/v3 (Go): affected all versions; fixed in 3.0.15

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-28681/ (Markdown: https://insights.sbomify.com/CVE-2021-28681/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-28681
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-28681
- OSV: https://osv.dev/vulnerability/CVE-2021-28681

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-28681/
Summaries are generated and may contain mistakes; the official description above is the record.