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FirecrackerApplication · Amazon

CVE-2019-18960

CRITICAL · 9.8 CVSS v3.1 Published 2019-12-11
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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 · unedited
Firecracker vsock implementation buffer overflow in versions 0.18.0 and 0.19.0. This can result in potentially exploitable crashes.

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 · moderate confidence

Buffer overflow vulnerability in Firecracker's vsock (virtual socket) implementation affecting versions 0.18.0 and 0.19.0. The overflow in the vsock device allows potentially exploitable crashes, meaning an attacker could potentially achieve code execution beyond just causing a denial of service.

MitigationUpgrade Firecracker to a version beyond 0.19.0 that contains the fix for this vulnerability. If immediate upgrading is not possible, consider disabling the vsock device if not required for the workload.

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
FirecrackerApplication
Affected:= 0.18.0= 0.19.0

CVSS 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
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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 checks

Work through these to decide whether this CVE applies to you.

  1. Check Firecracker version
    Run `firecracker --version` or check the firecracker binary metadata to identify the installed version number
    Affected if The version is exactly 0.18.0 or exactly 0.19.0
  2. Identify vsock device configuration
    Review the Firecracker microvm configuration file (typically JSON) for a vsock device definition with 'vsock' as the host_dev or in the devices section
    Affected if A vsock device is configured and attached to the microvm
  3. Verify vsock is actively used
    Check runtime configuration or inspect the running Firecracker process for active vsock device connections using process inspection tools
    Affected if The vsock device is present in the active microvm runtime configuration

The environment is affected if Firecracker version is 0.18.0 or 0.19.0 AND a vsock device is configured or active in the microvm configuration.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Firecracker to a version beyond 0.19.0 that contains the fix for this vulnerability. If immediate upgrading is not possible, consider disabling the vsock device if not required for the workload.

Fix this in Firecracker Scoped from the published advisory
  • Consultation2.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,800
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-18960 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data