x/vulndb: potential Go vuln in github.com/nats-io/nkeys

[bruth]

Acknowledgement

• The maintainer(s) of the affected project have already been made aware of this vulnerability.

Description

(This advisory is canonically https://advisories.nats.io/CVE/secnote-2023-02.txt)

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.
All usage of nkeys prior to the January 2023 0.4.0 release was
signing-only.

Within the nats-server, the encryption is used for the Auth
Callouts feature, introduced with 2.10.0 (September 2023).
The Auth Callout request includes the supplied user password.
These messages are sent within NATS, and should typically be in a
dedicated NATS Account used for callouts, but this is not required.
Thus in scenarios where the Callouts are in an account shared with
untrusted users or where the callout responders connect without TLS,
this may lead to user credential exposure.

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

Workarounds

None available.

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).

References

• GitHub Security Advisory for nkeys & nats-server:
  GHSA-mr45-rx8q-wcm9

Affected Modules, Packages, Versions and Symbols

Module: github.com/nats-io/nkeys
Package: github.com/nats-io/nkeys
Versions:
  - Introduced: 0.4.0
  - Fixed: 0.4.6
Symbols:
  - CreateCurveKeys
  - CreateCurveKeysWithRand

Module: github.com/nats-io/nats-server
Package: github.com/nats-io/nats-server/v2/server
Versions:
  - Introduced: 2.10.0
  - Fixed: 2.10.4

CVE/GHSA ID

CVE-2023-46129, GHSA-mr45-rx8q-wcm9

Fix Commit or Pull Request

nats-io/nkeys#59

References

• GitHub Security Advisory for nkeys & nats-server:
  GHSA-mr45-rx8q-wcm9

Additional information

No response

[neild]

Thanks for the report! I'd just finished writing the report for the automation-generated issue (#2163), so I'm going to mark this issue as a duplicate, but I appreciate the second notice.

[neild]

Duplicate of #2163