xkeys seal encryption used fixed key for all encryption

CVE-2023-46129 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

Background

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.

Problem Description

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.

Affected versions

nkeys Go library:
* 0.4.0 up to and including 0.4.5
* Fixed with nats-io/nkeys: 0.4.6

NATS Server:
* 2.10.0 up to and including 2.10.3
* Fixed with nats-io/nats-server: 2.10.4

Solution

Upgrade the nats-server.
For any application handling auth callouts in Go, if using the nkeys library, update the dependency, recompile and deploy that in lockstep.

Credits

Problem reported by Quentin Matillat (GitHub @tinou98).

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2023-10-31 21:19:02 UTC
Updated
2023-12-07 05:06:07 UTC
GitHub reviewed
2023-10-31 21:19:02 UTC
NVD published
2023-10-30

EPSS Score

Score Percentile
0.12% 31.49%

CVSS Scores

Base score Version Severity Vector
7.5 3.1 —
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

Type Value
GHSA GHSA-mr45-rx8q-wcm9 ↗
CVE CVE-2023-46129 ↗

CWEs

CWE id Name
CWE-321 Use of Hard-coded Cryptographic Key
CWE-325 Missing Cryptographic Step

Credits

  • tinou98 (finder)

Affected packages (2)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
go github.com/nats-io/nkeys >= 0.4.0, <= 0.4.5 0.4.6 —
go github.com/nats-io/nats-server/v2 >= 2.10.0, <= 2.10.3 2.10.4 —

References

cvelogic Threat Intelligence