Reactor NettyFramework / library · Pivotal

CVE-2019-11284

HIGH · 8.6 CVSS v3.1 Published 2019-10-17
Fix available
A fix is available. Upgrade to 0.8.11 or later.
See remediation →
95/100
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
Pivotal Reactor Netty, versions prior to 0.8.11, passes headers through redirects, including authorization ones. A remote unauthenticated malicious user may gain access to credentials for a different server than they have access to.

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

Pivotal Reactor Netty versions prior to 0.8.11 improperly forwards authorization headers during HTTP redirects. When the server issues a redirect response, sensitive authentication credentials are passed to the redirect target server, potentially exposing them to an unintended host.

MitigationUpgrade Reactor Netty to version 0.8.11 or later to prevent authorization headers from being forwarded through redirect responses.

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
Reactor NettyFramework / library
Affected:>= 0.8.0, < 0.8.11

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
Changed
Confidentiality
High
Integrity
None
Availability
None

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

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 Reactor Netty dependency
    Inspect your project's build file (pom.xml, build.gradle, build.gradle.kts) for the reactor-netty dependency. Also check for netty-transport-native-epoll or similar Reactor Netty JARs in your classpath or lib directory.
    Affected if The reactor-netty dependency is present with version 0.8.0 through 0.8.10 inclusive.
  2. Check installed Reactor Netty version
    Run 'mvn dependency:tree' for Maven projects or 'gradle dependencies' for Gradle projects to list the resolved reactor-netty version. Alternatively, locate the reactor-netty JAR file and inspect its manifest or use 'jar tf' to view package contents.
    Affected if The resolved version shows reactor-netty version 0.8.x where x is between 0 and 10.
  3. Verify HTTP client usage with authentication
    Search your codebase for uses of Reactor Netty's HttpClient with authorization headers, Basic Auth, Bearer tokens, or custom authentication headers. Look for patterns like HttpClient.create().headers(h -> h.setAuthorization(...)) or requests to endpoints that return 3xx redirects.
    Affected if Your application uses Reactor Netty's HttpClient to make requests with authorization headers to endpoints that may return redirect responses.
  4. Check for redirect-following behavior
    Review your HttpClient configuration for redirect settings. Look for .followRedirect(true) or similar redirect-handling configuration. Examine if the client automatically follows redirects without stripping authentication headers.
    Affected if The HttpClient is configured to follow redirects (default behavior) while sending authorization credentials to remote endpoints.

You are affected if your project uses Reactor Netty version 0.8.0 through 0.8.10 and makes HTTP requests with authorization headers that could be redirected to a different host.

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
Upgrade available Upgrade to 0.8.11 or later
Fixed in 0.8.11
Interim mitigation

Upgrade Reactor Netty to version 0.8.11 or later to prevent authorization headers from being forwarded through redirect responses.

Fix this in Reactor Netty Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing6.0 h
  • Review / QA3.0 h
13.0 hours of engineering $2,200
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,520.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2019-11284 — 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-2019-11284 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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