Akka HttpApplication · Lightbend

CVE-2023-33251

MEDIUM · 5.5 CVSS v3.1 Published 2023-05-21
Fix available
A fix is available. Upgrade to 10.5.2 or later.
See remediation →
57/100
Remediation priority · Elevated
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
When Akka HTTP before 10.5.2 accepts file uploads via the FileUploadDirectives.fileUploadAll directive, the temporary file it creates has too weak permissions: it is readable by other users on Linux or UNIX, a similar issue to CVE-2022-41946.

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

Akka HTTP before 10.5.2 contains a file permission vulnerability in the FileUploadDirectives.fileUploadAll directive. When handling file uploads, the framework creates temporary files with overly permissive access rights that allow other users on the same Linux/UNIX system to read the uploaded content, similar to CVE-2022-41946.

MitigationUpgrade to Akka HTTP version 10.5.2 or later which addresses the weak file permissions. As a secondary measure, ensure the system's temp directory (/tmp or equivalent) has restricted permissions to limit local user access.

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
Akka HttpApplication
Affected:< 10.5.2

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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 Akka HTTP version
    Check your build configuration (build.sbt, pom.xml, gradle.build) for the akka-http dependency and note the version number. Also check any included JAR files or lock files for akka-http-core version.
    Affected if The version is below 10.5.2 (e.g., 10.5.0, 10.4.x, 10.2.x, etc.)
  2. Locate file upload directive usage
    Search your codebase for imports and usage of akka.http.scaladsl.server.directives.FileUploadDirectives or the fileUploadAll method. Also check for fileUpload and fileUploadToTemp which share the same vulnerable code path.
    Affected if Your application code imports or uses FileUploadDirectives, particularly fileUploadAll, fileUpload, or fileUploadToTemp methods.
  3. Verify upload functionality is active
    Review your application routes and configuration to confirm that file upload endpoints exist and are reachable. Check for POST/PUT endpoints that handle multipart form data.
    Affected if The application has active HTTP endpoints that accept file uploads via the vulnerable directives.
  4. Check temp directory permissions
    On Linux/UNIX systems where your application runs, verify the permissions on the system's temp directory (typically /tmp). Run 'ls -ld /tmp' to see if other users have read/execute access.
    Affected if The temp directory allows other local users to read files (world-readable /tmp directory).

You are affected if your application uses Akka HTTP version below 10.5.2 AND has active file upload endpoints using FileUploadDirectives, particularly fileUploadAll, fileUpload, or fileUploadToTemp.

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 10.5.2 or later
Fixed in 10.5.2
Interim mitigation

Upgrade to Akka HTTP version 10.5.2 or later which addresses the weak file permissions. As a secondary measure, ensure the system's temp directory (/tmp or equivalent) has restricted permissions to limit local user access.

Recommended fix High confidence

10.5.2

  1. Upgrade Akka HTTP to version 10.5.2 or later by updating your build dependency (e.g., in sbt: scalaVersion := "2.13.x" and akkaHttpVersion := "10.5.2")
  2. After upgrading, verify that file uploads via FileUploadDirectives.fileUploadAll no longer create world-readable temporary files
Caveat Review Akka HTTP 10.5.x release notes for any potential breaking changes before upgrading in production environments

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

Fix this in Akka Http Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,328.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-33251 — 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-2023-33251 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
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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