Debian LinuxOperating system · Debian
CVE-2020-4067
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceIn coturn STUN/TURN server before version 4.5.1.3, the response buffer is not properly initialized, causing padding bytes to leak information between different client connections. An attacker can intelligently query the server to retrieve interesting bytes from the padding of another client's connection.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Debian LinuxOperating system
= 8.0= 9.0= 10.0
FedoraOperating system
= 31= 32
Ubuntu LinuxOperating system
= 16.04= 18.04= 19.10= 20.04< 4.5.1.3= 15.2CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Verify coturn is installedCheck if the coturn package is present. On Debian/Ubuntu: dpkg -l | grep coturn or apt list --installed | grep coturn. On Fedora: rpm -qa | grep coturn. Or check for the binary: which turnserverAffected if coturn is installed and the version is less than 4.5.1.3 or the version cannot be determined
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Determine installed coturn versionRun 'turnserver --version' or check the package version with your package manager (dpkg -l coturn, rpm -qi coturn, etc.)Affected if The version shown is before 4.5.1.3 (e.g., 4.5.1, 4.5.0, 4.4.x, etc.)
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Confirm TURN server is running and accessibleCheck if the turnserver process is running: ps aux | grep turnserver. Also verify the TURN port (default 3478) is listening: netstat -tulpn | grep 3478 or ss -tulpn | grep 3478Affected if The TURN server is running and accepting client connections, and the version is vulnerable
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Check if TURN authentication is enabledInspect the coturn configuration file (typically /etc/turnserver.conf or /etc/coturn/turnserver.conf) for static-auth or use-password lines. Also check if 'no-auth' is not setAffected if The TURN server accepts connections from untrusted clients (no authentication required) and the version is vulnerable
You are affected if you are running a coturn version earlier than 4.5.1.3 as either a TURN server accepting client connections or as a shared secret based relay, as the padding bytes from uninitialized memory can leak information between client sessions.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor data4.5.1.3
Upgrade coturn to version 4.5.1.3 or later to ensure proper buffer initialization.
Fix this in Debian Linux
Scoped from the published advisory
- Consultation1.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-4067 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-4067 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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