CVE-2018-4058
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 · uneditedAn exploitable unsafe default configuration vulnerability exists in the TURN server functionality of coTURN prior to 4.5.0.9. By default, the TURN server allows relaying external traffic to the loopback interface of its own host. This can provide access to other private services running on that host, which can lead to further attacks. An attacker can set up a relay with a loopback address as the peer on an affected TURN server to trigger this vulnerability.
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 confidencecoTURN TURN server prior to 4.5.0.9 has an unsafe default configuration that allows relaying external traffic to the loopback interface (127.0.0.1) of the host. Attackers can configure a relay with a loopback address as the peer, enabling them to access internal services running on localhost that should not be exposed.
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< 4.5.0.9CVSS 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
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/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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Identify coTURN installation and versionRun 'turnserver --version' or check the package manager for the installed coTURN versionAffected if The installed version is lower than 4.5.0.9
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Locate the coTURN configuration fileCommon locations include /etc/turnserver.conf or /etc/coturn/turnserver.conf; check the man page or documentation for your installationAffected if You cannot locate a configuration file (may indicate default configuration is in use)
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Inspect the deny-loopback-peers settingSearch the configuration file for 'deny-loopback-peers' or 'deny-loopback'; check if it is set to 'true' or 'yes'Affected if The directive is absent, set to 'false', or commented out (vulnerable default state)
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Verify relay configuration for loopback addressesReview any 'relay' or 'peer' settings in the configuration for 127.0.0.1 or ::1 addressesAffected if Loopback addresses are explicitly allowed as relay peers
You are affected if coTURN version is below 4.5.0.9 AND the deny-loopback-peers option is not enabled in the configuration, allowing external traffic to be relayed to localhost services.
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 data4.5.0.9
Upgrade to coTURN 4.5.0.9 or later, and configure the server to deny relaying to loopback addresses (deny-loopback-peers configuration option).
- Consultation3.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2018-4058 — 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-2018-4058 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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