EngineApplication · Docker
CVE-2020-13401
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 issue was discovered in Docker Engine before 19.03.11. An attacker in a container, with the CAP_NET_RAW capability, can craft IPv6 router advertisements, and consequently spoof external IPv6 hosts, obtain sensitive information, or cause a denial of service.
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 Docker Engine before 19.03.11, a container with CAP_NET_RAW capability can send crafted IPv6 router advertisements to spoof external IPv6 hosts, intercept traffic, or cause denial of service by disrupting IPv6 routing.
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
EngineApplication
< 19.03.11
FedoraOperating system
= 31= 32
Debian LinuxOperating system
= 10.0all versionsCVSS 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
- High
- Privileges
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L
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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Check Docker Engine versionRun `docker version --format '{{.Server.Version}}'` or `dockerd --version` to get the Docker Engine versionAffected if Version is less than 19.03.11 (e.g., 19.03.10, 19.03.9, etc.)
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Verify CAP_NET_RAW capability is available to containersCheck if the Docker daemon allows CAP_NET_RAW by inspecting running containers with `docker ps --format '{{.ID}}' | xargs docker inspect --format 'Container: {{.Id}}, CapAdd: {{.HostConfig.CapAdd}}'` or check default capabilities in `/etc/docker/daemon.json`Affected if Containers can be granted CAP_NET_RAW capability (any container with this capability can exploit the flaw)
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Check if IPv6 is enabled on Docker networksRun `docker network ls --format '{{.Name}}' | xargs -I {} docker network inspect {} --format 'Network: {{.Name}}, IPv6: {{.EnableIPv6}}'`Affected if IPv6 is enabled on any Docker bridge or custom network (the flaw allows IPv6 router advertisement spoofing)
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Identify containers currently running with CAP_NET_RAWRun `docker ps -q | xargs -I {} docker inspect {} --format '{{.Id}}: {{.HostConfig.CapAdd}}' | grep -i cap_net_raw`Affected if Any container is currently running with CAP_NET_RAW capability and Docker version is below 19.03.11
You are affected if Docker Engine version is below 19.03.11 AND any container can obtain CAP_NET_RAW capability AND IPv6 is enabled on your Docker networks.
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 data19.03.11
Upgrade Docker Engine to 19.03.11 or later. Additionally, avoid granting CAP_NET_RAW capability to untrusted containers or drop it entirely if IPv6 is not required.
Fix this in Engine
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,416.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-13401 — 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-2020-13401 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
- No weaponised exploit code, or anything meant to cause harm
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