CVE-2019-8849
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 · uneditedThe issue was addressed by signaling that an executable stack is not required. This issue is fixed in SwiftNIO SSL 2.4.1. A SwiftNIO application using TLS may be able to execute arbitrary code.
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 confidenceA critical memory corruption vulnerability in SwiftNIO SSL allows arbitrary code execution via TLS connections. The flaw was remediated by addressing executable stack requirements in the library's compiled components. This affects any SwiftNIO application using TLS functionality.
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< 2.4.1CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify SwiftNIO SSL package versionCheck your project's Package.swift, Package.resolved, or your dependency manager lock file (e.g., Package.resolved for Swift Package Manager, Podfile.lock for CocoaPods, or Cartfile.resolved for Carthage) for the swift-nio-ssl version numberAffected if The listed version is lower than 2.4.1 (e.g., 2.4.0, 2.3.0, etc.)
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Locate SwiftNIO SSL in dependenciesSearch your project for 'NIOSSL' imports in source files, or grep for 'swift-nio-ssl' in your dependency configuration filesAffected if SwiftNIO SSL is declared as a dependency in your project
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Verify TLS usage in applicationSearch source code for NIOSSL-specific configuration such as 'try NIOSSLServerConfiguration', 'try NIOSSLClientConfiguration', 'NIOSSLContext', or calls to 'applyTLS' methodsAffected if Your application configures or uses TLS through SwiftNIO SSL APIs (the vulnerability only applies when TLS functionality is actively used)
You are affected if your installed SwiftNIO SSL version is below 2.4.1 AND your application uses SwiftNIO's TLS/SSL functionality for handling encrypted connections.
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 · scoped2.4.1
Upgrade SwiftNIO SSL to version 2.4.1 or later to address the executable stack vulnerability that enables arbitrary code execution.
SwiftNIO SSL 2.4.1
- Update the SwiftNIO SSL dependency in your project to version 2.4.1 or later
- If using Swift Package Manager, update the Package.swift dependency specification to specify swift-nio-ssl version 2.4.1 or higher
- Rebuild and test the application to verify the upgrade does not introduce regressions
- Redeploy the updated application
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,464.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-8849 — 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-2019-8849 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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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.
- 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