CVE-2021-27376: Nb connect :net::SocketAddr Vulnerability

CRITICAL
Advisory Identifier: GHSA-rm4w-6696-r77p
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CVSS 9.8
CWE-119
Published
Advisory Summary

CVE-2021-27376 is a CRITICAL (CVSS 9.8) :net::socketaddr vulnerability (CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer) affecting Nb connect libraries in the crates.io ecosystem. The issue involves :net::socketaddr. Remediation is available by upgrading affected packages to version 1.0.3.

CVE-2021-27376 at a Glance

CVE Identifier CVE-2021-27376
GHSA Identifier GHSA-rm4w-6696-r77p
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer
Affected Product Nb connect
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2021-27376

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

nb-connect fixed: 1.0.3 
Upgrade nb-connect to 1.0.3
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 nb-connect

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-27376, inspect your project dependencies for Nb connect:

inspect dependencies for nb-connect

Analyze the terminal output to locate any version of Nb connect in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.0.3), 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-119: Improper Restriction of Operations within the Bounds of a Memory Buffer, where the product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. this may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data. In Nb connect, 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 nb-connect crate has assumed std::net::SocketAddrV4 and std::net::SocketAddrV6 have the same memory layout as the system C representation sockaddr. It has simply casted the pointers to convert the socket addresses to the system representation. The standard library does not say anything about the memory layout, and this will cause invalid memory access if the standard library changes the implementation. No warnings or errors will be emitted once the change happens.

CVE-2021-27376 Affected Nb connect Versions

1 component(s)
Fixed Versions:
1.0.3
Product / Package Ecosystem Affected Versions Fixed Version
nb-connect
 crates.io
< 1.0.3
1.0.3

References

NVD — CVE-2021-27376 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-27376
Nb connect Source Repository REPOSITORY
https://github.com/smol-rs/nb-connect/issues/1
Nb connect Source Repository REPOSITORY
https://github.com/smol-rs/nb-connect
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2021-0021.html

Frequently Asked Questions

What is CVE-2021-27376?
CVE-2021-27376 is a security vulnerability in Nb connect involving :net::SocketAddr under CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer.
Which Nb connect versions are affected?
Affected versions include releases prior to 1.0.3 across affected packages: nb-connect.
What version fixes CVE-2021-27376?
Upgrading to 1.0.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is nb-connect affected?
Yes, nb-connect is affected in releases prior to 1.0.3. Upgrade your dependency to 1.0.3 or later.
What is the CVSS score of CVE-2021-27376?
CVE-2021-27376 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2021-27376?
CVE-2021-27376 is classified under CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer (The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.).
How can I check crates.io dependencies for CVE-2021-27376?
Run the dependency tree command: 'inspect dependencies for nb-connect'. 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-rm4w-6696-r77p",
  "modified" : "2023-06-13T18:30:56Z",
  "published" : "2021-08-25T20:52:14Z",
  "aliases" : [ "CVE-2021-27376" ],
  "summary" : "nb-connect invalidly assumes the memory layout of std::net::SocketAddr",
  "details" : "The nb-connect crate has assumed std::net::SocketAddrV4 and std::net::SocketAddrV6 have the same memory layout as the system C representation sockaddr. It has simply casted the pointers to convert the socket addresses to the system representation. The standard library does not say anything about the memory layout, and this will cause invalid memory access if the standard library changes the implementation. No warnings or errors will be emitted once the change happens.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "nb-connect"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.0.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-27376"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/smol-rs/nb-connect/issues/1"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/smol-rs/nb-connect"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2021-0021.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-119" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-19T17:34:37Z",
    "nvd_published_at" : null
  }
}