Race ConditionWeakness · CWE-362

CVE-2024-27983

HIGH · 8.2 CVSS v3.0 Published 2024-04-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
91/100
Remediation priority · Urgent
High EPSS 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
An attacker can make the Node.js HTTP/2 server completely unavailable by sending a small amount of HTTP/2 frames packets with a few HTTP/2 frames inside. It is possible to leave some data in nghttp2 memory after reset when headers with HTTP/2 CONTINUATION frame are sent to the server and then a TCP connection is abruptly closed by the client triggering the Http2Session destructor while header frames are still being processed (and stored in memory) causing a race condition.

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

An attacker can render a Node.js HTTP/2 server completely unavailable by sending specially crafted HTTP/2 frames containing CONTINUATION frames followed by an abrupt TCP connection closure. This triggers a race condition in the Http2Session destructor where header frames remain in memory during processing, causing the server to crash or become unresponsive.

MitigationUpgrade Node.js to a version that addresses this vulnerability; if immediate patching is not feasible, consider disabling HTTP/2 or implementing upstream rate limiting and connection controls at a reverse proxy.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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
None
Integrity
Low
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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. Identify Node.js installation and version
    Run 'node --version' to obtain the Node.js version number
    Affected if The installed version falls within the range of versions known to be vulnerable to this HTTP/2 race condition flaw
  2. Determine if HTTP/2 is in use
    Inspect application code or server configuration for use of the Node.js 'http2' module, or check if the server exposes HTTP/2 endpoints (listen on h2 protocol)
    Affected if HTTP/2 is enabled and the server accepts HTTP/2 connections on any endpoint
  3. Check for exposed HTTP/2 server configurations
    Review any Node.js server scripts that create Http2Server instances or use the 'http2' module with 'createServer()' or 'createSecureServer()'
    Affected if The application creates HTTP/2 servers or uses HTTP/2 multiplexing features
  4. Inspect reverse proxy or load balancer HTTP/2 settings
    If Node.js sits behind a proxy (nginx, HAProxy, etc.), check whether HTTP/2 pass-through or upgrade is configured
    Affected if HTTP/2 traffic is being forwarded to the Node.js backend server
  5. Verify network exposure of HTTP/2 service
    Scan listening ports or review firewall rules to confirm HTTP/2 services are reachable from untrusted networks
    Affected if The HTTP/2 service is exposed to the internet or untrusted users who could send malicious CONTINUATION frames

A user is affected if they run a vulnerable Node.js version with HTTP/2 enabled and exposed, where remote attackers can send specially crafted HTTP/2 CONTINUATION frames followed by abrupt TCP closure to trigger the race condition.

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 Node.js to a version that addresses this vulnerability; if immediate patching is not feasible, consider disabling HTTP/2 or implementing upstream rate limiting and connection controls at a reverse proxy.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2024-27983 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-27983 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
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