Swiftnio Http\/2Application · Apple

CVE-2022-24668

HIGH · 7.5 CVSS v3.1 Published 2022-02-09
Fix available
A fix is available. Upgrade to 1.19.2 or later.
See remediation →
84/100
Remediation priority · High
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
A program using swift-nio-http2 is vulnerable to a denial of service attack caused by a network peer sending ALTSVC or ORIGIN frames. This attack affects all swift-nio-http2 versions from 1.0.0 to 1.19.1. This vulnerability is caused by a logical error after frame parsing but before frame handling. ORIGIN and ALTSVC frames are not currently supported by swift-nio-http2, and should be ignored. However, one code path that encounters them has a deliberate trap instead. This was left behind from the original development process and was never removed. Sending an ALTSVC or ORIGIN frame does not require any special permission, so any HTTP/2 connection peer may send such a frame. For clients, this means any server to which they connect may launch this attack. For servers, anyone they allow to connect to them may launch such an attack. The attack is low-effort: it takes very little resources to send one of these frames. The impact on availability is high: receiving the frame immediately crashes the server, dropping all in-flight connections and causing the service to need to restart. It is straightforward for an attacker to repeatedly send these frames, so attackers require very few resources to achieve a substantial denial of service. The attack does not have any confidentiality or integrity risks in and of itself. This is a controlled, intentional crash. However, sudden process crashes can lead to violations of invariants in services, so it is possible that this attack can be used to trigger an error condition that has confidentiality or integrity risks. The risk can be mitigated if untrusted peers can be prevented from communicating with the service. This mitigation is not available to many services. The issue is fixed by rewriting the parsing code to correctly handle the condition. The issue was found by automated fuzzing by oss-fuzz.

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 confidence

swift-nio-http2 versions 1.0.0-1.19.1 contain a denial-of-service vulnerability where ALTSVC or ORIGIN frames (which are unsupported but should be ignored) trigger an intentional debug trap left from development. When these frames are received, the server immediately crashes due to this logical error between parsing and handling, dropping all connections.

MitigationUpgrade swift-nio-http2 to a version beyond 1.19.1 where the parsing code correctly handles these frames by ignoring them rather than crashing. If immediate upgrade is not possible, restrict network access to trusted peers only.

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
Swiftnio Http\/2Application
Affected:>= 1.0.0, < 1.19.2

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
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 swift-nio-http2 in your project
    Search your project dependencies for swift-nio-http2 by inspecting Package.swift, Package.resolved, or your dependency management file (Podfile, Cartfile, etc.) for the package name
    Affected if The package is present in your dependencies
  2. Determine the installed swift-nio-http2 version
    Check Package.resolved for the exact version number, or run swift package show-dependencies to list all resolved versions
    Affected if The version is 1.0.0 through 1.19.1 (inclusive)
  3. Verify HTTP/2 is enabled in your application
    Search your source code for HTTP/2 configuration: look for HTTP2Handler, HTTP2StreamMultiplexer, NIOHTTP2ServerPipeline, or Application.serverConfiguration.http2 settings
    Affected if Your application configures and uses HTTP/2 protocol handling
  4. Check for crash logs indicating frame handling failures
    Review server crash logs or error output for mentions of ALTSVC, ORIGIN, or HTTP/2 frame parsing failures occurring during normal request processing
    Affected if The server crashes with errors related to ALTSVC or ORIGIN frame handling

Your environment is affected if swift-nio-http2 version 1.0.0 through 1.19.1 is present AND your application processes HTTP/2 traffic.

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.

dbcve · scoped
Upgrade available Upgrade to 1.19.2 or later
Fixed in 1.19.2
Interim mitigation

Upgrade swift-nio-http2 to a version beyond 1.19.1 where the parsing code correctly handles these frames by ignoring them rather than crashing. If immediate upgrade is not possible, restrict network access to trusted peers only.

Recommended fix High confidence

swift-nio-http2 version 1.19.2

  1. Update the swift-nio-http2 dependency in your Package.swift file to version 1.19.2 or later
  2. Run swift package update or regenerate your Package.resolved file
  3. Rebuild your project to verify the update was applied correctly
  4. Verify the server no longer crashes when receiving ALTSVC or ORIGIN frames

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Swiftnio Http\/2 Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,920
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Scan for this in your stack

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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-2022-24668 in production — separate from our analysis above.

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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
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  • Version or environment caveats, and links to real fixes
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