# CVE-2020-4067: coturn: In coturn before version 4.5.1.3, there is an issue whereby STUN/TURN response buffer is not initialized properly

CVE-2020-4067 is fixed in coturn on 1 platform, first by coturn 4.5.0.7-1ubuntu2.18.04.2, released June 29, 2020. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2020-4067
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0190
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 29, 2020

## Description

In coturn before version 4.5.1.3, there is an issue whereby STUN/TURN response buffer is not initialized properly. There is a leak of information between different client connections. One client (an attacker) could use their connection to intelligently query coturn to get interesting bytes in the padding bytes from the connection of another client. This has been fixed in 4.5.1.3.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | coturn Ubuntu 18.04.6 LTS (bionic) | 4.5.0.7-1ubuntu2.18.04.2 | [coturn 4.5.0.7-1ubuntu2.18.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-coturn-4.5.0.7-1ubuntu2.18.04.2.md) | Jun 29, 2020 |
| Linux | coturn Ubuntu 20.04 LTS (focal) | 4.5.1.1-1.1ubuntu0.20.04.1 | [coturn 4.5.1.1-1.1ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-coturn-4.5.1.1-1.1ubuntu0.20.04.1.md) | Jun 29, 2020 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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