GHSA-wvc4-j7g5-4f79: Nats NATS TLS Certificate Common Name Vulnerability

MODERATE
Share
CWE-347
Published
Advisory Summary

GHSA-wvc4-j7g5-4f79 is a MODERATE nats tls certificate common name vulnerability (CWE-347: Improper Verification of Cryptographic Signature) affecting Nats libraries in the crates.io ecosystem. The issue involves nats tls certificate common name validation bypass. Remediation is available by upgrading affected packages to version 0.24.1.

GHSA-wvc4-j7g5-4f79 at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-wvc4-j7g5-4f79
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-347: Improper Verification of Cryptographic Signature
Affected Product Nats
Package Ecosystem crates.io
Published Date
Last Updated

How to Fix GHSA-wvc4-j7g5-4f79

To remediate this vulnerability, upgrade all affected Nats dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

nats fixed: 0.24.1 
Upgrade nats to 0.24.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for nats

How to Check if You Are Affected

To determine whether your application is affected by GHSA-wvc4-j7g5-4f79, inspect your project dependencies for Nats:

inspect dependencies for nats

Analyze the terminal output to locate any version of Nats in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.24.1), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-347: Improper Verification of Cryptographic Signature, where the product does not verify, or incorrectly verifies, the cryptographic signature for data. In Nats, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

The NATS official Rust clients are vulnerable to MitM when using TLS. A fix for the `nats` crate hasn't been released yet. Since the `nats` crate is going to be deprecated anyway, consider switching to `async-nats` `>= 0.29` which already fixed this vulnerability. The common name of the server's TLS certificate is validated against the `host`name provided by the server's plaintext `INFO` message during the initial connection setup phase. A MitM proxy can tamper with the `host` field's value by substituting it with the common name of a valid certificate it controls, fooling the client into accepting it. ## Reproduction steps 1. The NATS Rust client tries to establish a new connection 2. The connection is intercepted by a MitM proxy 3. The proxy makes a separate connection to the NATS server 4. The NATS server replies with an `INFO` message 5. The proxy reads the `INFO`, alters the `host` JSON field and passes the tampered `INFO` back to the client 6. The proxy upgrades the client connection to TLS, presenting a certificate issued by a certificate authority present in the client's keychain. In the previous step the `host` was set to the common name of said certificate 7. `rustls` accepts the certificate, having verified that the common name matches the attacker-controlled value it was given 9. The client has been fooled by the MitM proxy into accepting the attacker-controlled certificate

GHSA-wvc4-j7g5-4f79 Affected Nats Versions

1 component(s)
Fixed Versions:
0.24.1
Product / Package Ecosystem Affected Versions Fixed Version
nats
 crates.io
≥ 0.9.0
< 0.24.1
0.24.1

References

Nats Source Repository REPOSITORY
https://github.com/nats-io/nats.rs/pull/881
Nats Source Repository REPOSITORY
https://github.com/nats-io/nats.rs/pull/887
Security Fix Commit FIX COMMIT
https://github.com/nats-io/nats.rs/commit/9bacb86a480803ece9d1a45aa443081cf1eb815c
Nats Source Repository REPOSITORY
https://github.com/nats-io/nats.rs
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2023-0029.html

Frequently Asked Questions

What is GHSA-wvc4-j7g5-4f79?
GHSA-wvc4-j7g5-4f79 is a security vulnerability in Nats involving NATS TLS certificate common name validation bypass under CWE-347: Improper Verification of Cryptographic Signature.
Which Nats versions are affected?
Affected versions include releases prior to 0.24.1 across affected packages: nats.
What version fixes GHSA-wvc4-j7g5-4f79?
Upgrading to 0.24.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is nats affected?
Yes, nats is affected in releases prior to 0.24.1. Upgrade your dependency to 0.24.1 or later.
What CWE is associated with GHSA-wvc4-j7g5-4f79?
GHSA-wvc4-j7g5-4f79 is classified under CWE-347: Improper Verification of Cryptographic Signature (The product does not verify, or incorrectly verifies, the cryptographic signature for data.).
How can I check crates.io dependencies for GHSA-wvc4-j7g5-4f79?
Run the dependency tree command: 'inspect dependencies for nats'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-wvc4-j7g5-4f79",
  "modified" : "2023-03-27T21:12:24Z",
  "published" : "2023-03-27T21:12:24Z",
  "aliases" : [ ],
  "summary" : "NATS TLS certificate common name validation bypass",
  "details" : "The NATS official Rust clients are vulnerable to MitM when using TLS.\n\nA fix for the `nats` crate hasn't been released yet. Since the `nats` crate is going to be deprecated anyway, consider switching to `async-nats` `>= 0.29` which already fixed this vulnerability.\n\nThe common name of the server's TLS certificate is validated against the `host`name provided by the server's plaintext `INFO` message during the initial connection setup phase. A MitM proxy can tamper with the `host` field's value by substituting it with the common name of a valid certificate it controls, fooling the client into accepting it.\n\n## Reproduction steps\n\n1. The NATS Rust client tries to establish a new connection\n2. The connection is intercepted by a MitM proxy\n3. The proxy makes a separate connection to the NATS server\n4. The NATS server replies with an `INFO` message\n5. The proxy reads the `INFO`, alters the `host` JSON field and passes the tampered `INFO` back to the client\n6. The proxy upgrades the client connection to TLS, presenting a certificate issued by a certificate authority present in the client's keychain. In the previous step the `host` was set to the common name of said certificate\n7. `rustls` accepts the certificate, having verified that the common name matches the attacker-controlled value it was given\n9. The client has been fooled by the MitM proxy into accepting the attacker-controlled certificate\n",
  "severity" : [ ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "nats"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.9.0"
      }, {
        "fixed" : "0.24.1"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.24.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/nats-io/nats.rs/pull/881"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nats-io/nats.rs/pull/887"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nats-io/nats.rs/commit/9bacb86a480803ece9d1a45aa443081cf1eb815c"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/nats-io/nats.rs"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2023-0029.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-347" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-03-27T21:12:24Z",
    "nvd_published_at" : null
  }
}