dbcve.org
Nats ServerApplication · Linuxfoundation

CVE-2023-46129

HIGH · 7.5 CVSS v3.1 Published 2023-10-31
Fix available
A fix is available. Upgrade to 0.4.6 / 2.10.4 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
NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. The cryptographic key handling library, nkeys, recently gained support for encryption, not just for signing/authentication. This is used in nats-server 2.10 (Sep 2023) and newer for authentication callouts. In nkeys versions 0.4.0 through 0.4.5, corresponding with NATS server versions 2.10.0 through 2.10.3, the nkeys library's `xkeys` encryption handling logic mistakenly passed an array by value into an internal function, where the function mutated that buffer to populate the encryption key to use. As a result, all encryption was actually to an all-zeros key. This affects encryption only, not signing. FIXME: FILL IN IMPACT ON NATS-SERVER AUTH CALLOUT SECURITY. nkeys Go library 0.4.6, corresponding with NATS Server 2.10.4, has a patch for this issue. No known workarounds are available. For any application handling auth callouts in Go, if using the nkeys library, update the dependency, recompile and deploy that in lockstep.

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 confidence

The nkeys Go library versions 0.4.0-0.4.5 incorrectly passed an array by value into an internal encryption function, which mutated the buffer to populate the encryption key. Due to this pass-by-value bug, all encryption operations used an all-zeros key instead of the intended cryptographic key. This affects NATS Server 2.10.0-2.10.3's authentication callout encryption, rendering any encrypted auth callout data effectively plaintext.

MitigationUpdate nkeys library to version 0.4.6 and NATS Server to version 2.10.4 or later, then recompile and redeploy affected services. No workarounds exist.

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
Nats ServerApplication
Affected:>= 2.10.0, < 2.10.4
NkeysApplication
Affected:>= 0.4.0, < 0.4.6

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
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/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. Check NATS Server version
    Run `nats-server --version` or inspect the nats-server binary with `nats-server -version`. If using a package manager, use `rpm -q nats-server` or `dpkg -l nats-server`. Check the binary file metadata or deployment manifests if deployed from custom builds.
    Affected if The version is 2.10.0, 2.10.1, 2.10.2, or 2.10.3 (versions 2.10.0 to <2.10.4)
  2. Check nkeys library version
    Inspect your Go module dependencies. Run `go list -m all | grep nkeys` in the project directory, or check go.mod and go.sum files for `github.com/nkeys v0.4.x`. If using vendored dependencies, examine the vendor directory for the nkeys library version.
    Affected if The nkeys library version is 0.4.0, 0.4.1, 0.4.2, 0.4.3, 0.4.4, or 0.4.5 (versions 0.4.0 to <0.4.6)
  3. Verify authentication callout is enabled
    Examine the NATS Server configuration file (typically nats-server.conf) for the `authorization_callout` directive or similar auth callout configuration. Check for entries like `authorization_callout { ... }` or `auth_callout` in the config file.
    Affected if The configuration file contains an active authorization_callout block that enables encrypted auth callout functionality
  4. Inspect auth callout encryption configuration
    Within the auth callout block, look for settings that indicate encrypted payload handling. Check whether the server is configured to send or receive encrypted data to the auth callout endpoint.
    Affected if Auth callout is configured to transmit sensitive data that should be encrypted but is now effectively plaintext due to the zero-key bug

You are affected if NATS Server 2.10.0-2.10.3 or nkeys library 0.4.0-0.4.5 is deployed AND authentication callout encryption is actively configured and in use.

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 0.4.6 / 2.10.4 or later
Fixed in 0.4.62.10.4
Interim mitigation

Update nkeys library to version 0.4.6 and NATS Server to version 2.10.4 or later, then recompile and redeploy affected services. No workarounds exist.

Recommended fix High confidence

NATS Server 2.10.4 and nkeys 0.4.6

  1. Check current nkeys library version in use (e.g., run `go list -m all | grep nkeys` or inspect go.mod)
  2. Update nkeys to version 0.4.6 or later: `go get github.com/nats-io/[email protected]`
  3. Update NATS Server to version 2.10.4 or later: `go get github.com/nats-io/nats-server/[email protected]`
  4. Run `go mod tidy` to clean up dependencies
  5. Recompile the application with `go build`
  6. Verify the fix by checking that nkeys version is >= 0.4.6 and nats-server version is >= 2.10.4
  7. Test authentication callout functionality to confirm encryption is working correctly

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

Fix this in Nats Server Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,920
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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-2023-46129 in production — separate from our analysis above.

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What this is

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  • Version or environment caveats, and links to real fixes
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