dbcve.org
Akka ActorApplication · Lightbend

CVE-2023-31442

HIGH · 7.5 CVSS v3.1 Published 2023-05-11
Fix available
A fix is available. Upgrade to 2.8.1 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
In Lightbend Akka before 2.8.1, the async-dns resolver (used by Discovery in DNS mode and transitively by Cluster Bootstrap) uses predictable DNS transaction IDs when resolving DNS records, making DNS resolution subject to poisoning by an attacker. If the application performing discovery does not validate (e.g., via TLS) the authenticity of the discovered service, this may result in exfiltration of application data (e.g., persistence events may be published to an unintended Kafka broker). If such validation is performed, then the poisoning constitutes a denial of access to the intended service. This affects Akka 2.5.14 through 2.8.0, and Akka Discovery through 2.8.0.

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

The async-dns resolver in Akka uses predictable DNS transaction IDs when resolving DNS records, enabling DNS poisoning attacks. This affects Akka's Service Discovery in DNS mode and Cluster Bootstrap, allowing attackers to redirect service endpoints to malicious servers.

MitigationUpgrade Akka to version 2.8.1 or later which implements random DNS transaction IDs. As a defense-in-depth measure, ensure all inter-service communication uses TLS certificate validation.

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 ActorApplication
Affected:>= 2.5.14, < 2.8.1
Akka DiscoveryApplication
Affected:< 2.8.1

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 installed Akka Actor version
    Inspect your build configuration file (build.sbt, pom.xml, or build.gradle) for the akka-actor dependency version, or run a dependency tree command like `sbt dependencyTree` or `mvn dependency:tree` to find the akka-actor version
    Affected if The version is >= 2.5.14 and < 2.8.1
  2. Identify installed Akka Discovery version
    Inspect your build configuration for the akka-discovery dependency version, or check your dependency tree output for akka-discovery module
    Affected if The version is < 2.8.1 (any version below 2.8.1 is affected if using DNS-based service discovery)
  3. Check if DNS-based service discovery is enabled
    Inspect your Akka configuration files (application.conf or reference.conf) for the discovery method setting under `akka.discovery`. Look for `method = dns` or a DNS-based discovery implementation
    Affected if The discovery method is set to DNS (method = dns) or uses a DNS-based resolver for service discovery
  4. Check if Cluster Bootstrap is enabled
    Inspect your Akka cluster configuration for `akka.cluster.bootstrap` settings. Look for cluster bootstrap related configuration blocks that enable DNS-based bootstrapping
    Affected if Cluster Bootstrap is configured and uses DNS for discovery (the default behavior)
  5. Verify DNS resolution is performed by Akka
    Review application logs or network traces during service startup to confirm Akka performs its own DNS lookups for service discovery rather than relying on a system resolver
    Affected if Akka performs DNS queries directly through its async-dns resolver (this is required for the vulnerability to be exploitable)

You are affected if you have Akka Actor >= 2.5.14 or Akka Discovery < 2.8.1 AND you use Akka's built-in DNS-based service discovery or Cluster Bootstrap for service resolution.

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 2.8.1 or later
Fixed in 2.8.1
Interim mitigation

Upgrade Akka to version 2.8.1 or later which implements random DNS transaction IDs. As a defense-in-depth measure, ensure all inter-service communication uses TLS certificate validation.

Recommended fix High confidence

2.8.1

  1. Upgrade Akka Actor from any version >= 2.5.14 and < 2.8.1 to version 2.8.1 or later
  2. If using Akka Discovery (for DNS-based service discovery), upgrade to version 2.8.1 or later
  3. If using Cluster Bootstrap with DNS-based discovery, ensure the Akka dependencies are all aligned to 2.8.1 or later
  4. After upgrading, verify that DNS resolution uses cryptographically random transaction IDs rather than predictable ones
  5. Test that service discovery and cluster formation work correctly with the updated dependencies
Caveat Review Akka 2.8.x release notes for any breaking changes from your current minor version

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

Fix this in Akka Actor Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,760
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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-2023-31442 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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data