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

Moderate severity GitHub Reviewed Published Mar 18, 2021 in pion/webrtc • Updated Aug 29, 2023

Package

gomod github.com/pion/webrtc/v3 (Go)

Affected versions

< 3.0.15

Patched versions

3.0.15

Description

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 pion/webrtc@545613d

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:

Thank you to https://github.com/Gaukas for discovering this.

References

@Sean-Der Sean-Der published to pion/webrtc Mar 18, 2021
Reviewed May 21, 2021
Published to the GitHub Advisory Database May 25, 2021
Last updated Aug 29, 2023

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS score

0.126%
(48th percentile)

Weaknesses

CVE ID

CVE-2021-28681

GHSA ID

GHSA-74xm-qj29-cq8p

Source code

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