CVE-2022-24666
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 · uneditedA program using swift-nio-http2 is vulnerable to a denial of service attack, caused by a network peer sending a specially crafted HTTP/2 frame. This attack affects all swift-nio-http2 versions from 1.0.0 to 1.19.1. This vulnerability is caused by a logical error when parsing a HTTP/2 HEADERS frame where the frame contains priority information without any other data. This logical error caused confusion about the size of the frame, leading to a parsing error. This parsing error immediately crashes the entire process. Sending a HEADERS frame with HTTP/2 priority information 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 an appropriately crafted frame. 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 appropriately crafted 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: swift-nio-http2 is parsing the frame in memory-safe code, so the crash is safe. 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 confidenceswift-nio-http2 contains a logical error in HTTP/2 HEADERS frame parsing. When a frame contains priority information without other data, the parser miscalculates frame size, triggering a parsing error that immediately crashes the entire process. Any HTTP/2 peer can send this crafted HEADERS frame without special permissions.
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>= 1.0.0, < 1.19.2CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify swift-nio-http2 dependencyInspect your project dependency manifest: check Package.swift for PackageDependency, Package.resolved for resolved versions, or Podfile.lock if using CocoaPods, or your build system's lock file for swift-nio-http2Affected if swift-nio-http2 appears as a direct or transitive dependency
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Determine installed versionLocate the specific version number of swift-nio-http2 in your dependency lock file (e.g., Package.resolved shows 'version' or 'revision')Affected if The version is 1.0.0 or higher but below 1.19.2
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Verify HTTP/2 usageInspect your application code or configuration for NIO HTTP/2 setup - look for NIOTSHTTP2Handler, HTTP2StreamChannel, or NIOHTTP2Handler usage in your server initializationAffected if Your application configures and uses HTTP/2 connections (the vulnerability triggers on incoming HTTP/2 traffic)
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Check runtime binary versionIf the library is compiled into your binary, search for the embedded swift-nio-http2 version string using strings your_binary | grep -i nio-http2 or a hex viewer, or check the compiled NIOHTTP2Handler moduleAffected if The runtime binary contains swift-nio-http2 version below 1.19.2
You are affected if your project depends on swift-nio-http2 with version 1.0.0 through 1.19.1 and your application accepts HTTP/2 connections from untrusted peers.
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.
dbcve · scoped1.19.2
Upgrade swift-nio-http2 to version 1.19.2 or later, which contains the corrected parsing logic. If upgrading is not immediately possible, restrict HTTP/2 connections to trusted peers only.
swift-nio-http2 version 1.19.2 or later
- 1. Identify all projects and dependencies that use swift-nio-http2 version < 1.19.2
- 2. Update the Package.swift file to specify swift-nio-http2 version 1.19.2 or later (e.g., .package(url: "https://github.com/apple/swift-nio-http2.git", from: "1.19.2"))
- 3. Run 'swift package resolve' to fetch the updated dependency
- 4. Rebuild and test the application to verify the fix works correctly
- 5. Deploy the updated application to replace vulnerable instances
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2022-24666 — 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-2022-24666 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
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- Version or environment caveats, and links to real fixes
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