CVE-2020-36471: Generator Data Races Vulnerability

MODERATE
Advisory Identifier: GHSA-w3g5-2848-2v8r
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CVSS 5.9
CWE-362
Published
Advisory Summary

CVE-2020-36471 is a MODERATE (CVSS 5.9) data races vulnerability (CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')) affecting Generator libraries in the crates.io ecosystem. The issue involves data races in generator. Remediation is available by upgrading affected packages to version 0.7.0.

CVE-2020-36471 at a Glance

CVE Identifier CVE-2020-36471
GHSA Identifier GHSA-w3g5-2848-2v8r
Severity MODERATE
CVSS v3.1 Base Score 5.9
CWE Classification CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Affected Product Generator
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 5.9

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

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

How to Fix CVE-2020-36471

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

generator fixed: 0.7.0 
Upgrade generator to 0.7.0
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 generator

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-36471, inspect your project dependencies for Generator:

inspect dependencies for generator

Analyze the terminal output to locate any version of Generator in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.7.0), 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-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'), where the product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently. In Generator, 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 `Generator` type is an iterable which uses a generator function that yields values. In affected versions of the crate, the provided function yielding values had no `Send` bounds despite the `Generator` itself implementing `Send`. The generator function lacking a `Send` bound means that types that are dangerous to send across threads such as `Rc` could be sent as part of a generator, potentially leading to data races. This flaw was fixed in commit [`f7d120a3b`](https://github.com/Xudong-Huang/generator-rs/commit/f7d120a3b724d06a7b623d0a4306acf8f78cb4f0) by enforcing that the generator function be bound by `Send`.

CVE-2020-36471 Affected Generator Versions

1 component(s)
Fixed Versions:
0.7.0
Product / Package Ecosystem Affected Versions Fixed Version
generator
 crates.io
< 0.7.0
0.7.0

References

NVD — CVE-2020-36471 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-36471
Generator Source Repository REPOSITORY
https://github.com/Xudong-Huang/generator-rs/issues/27
Security Fix Commit FIX COMMIT
https://github.com/Xudong-Huang/generator-rs/commit/f7d120a3b724d06a7b623d0a4306acf8f78cb4f0
Generator Source Repository REPOSITORY
https://github.com/Xudong-Huang/generator-rs
raw.githubusercontent.com/rustsec/advisory-db... WEB
https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/generator/RUSTSEC-2020-0151.md
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2020-0151.html

Frequently Asked Questions

What is CVE-2020-36471?
CVE-2020-36471 is a security vulnerability in Generator involving Data races in generator under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition').
Which Generator versions are affected?
Affected versions include releases prior to 0.7.0 across affected packages: generator.
What version fixes CVE-2020-36471?
Upgrading to 0.7.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is generator affected?
Yes, generator is affected in releases prior to 0.7.0. Upgrade your dependency to 0.7.0 or later.
What is the CVSS score of CVE-2020-36471?
CVE-2020-36471 has a CVSS v3.1 base score of 5.9 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2020-36471?
CVE-2020-36471 is classified under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') (The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.).
How can I check crates.io dependencies for CVE-2020-36471?
Run the dependency tree command: 'inspect dependencies for generator'. 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-w3g5-2848-2v8r",
  "modified" : "2021-08-24T18:04:25Z",
  "published" : "2021-08-25T20:57:05Z",
  "aliases" : [ "CVE-2020-36471" ],
  "summary" : "Data races in generator",
  "details" : "The `Generator` type is an iterable which uses a generator function that yields\nvalues. In affected versions of the crate, the provided function yielding values\nhad no `Send` bounds despite the `Generator` itself implementing `Send`.\n\nThe generator function lacking a `Send` bound means that types that are\ndangerous to send across threads such as `Rc` could be sent as part of a\ngenerator, potentially leading to data races.\n\nThis flaw was fixed in commit [`f7d120a3b`](https://github.com/Xudong-Huang/generator-rs/commit/f7d120a3b724d06a7b623d0a4306acf8f78cb4f0)\nby enforcing that the generator function be bound by `Send`.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "generator"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.7.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-36471"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Xudong-Huang/generator-rs/issues/27"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Xudong-Huang/generator-rs/commit/f7d120a3b724d06a7b623d0a4306acf8f78cb4f0"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/Xudong-Huang/generator-rs"
  }, {
    "type" : "WEB",
    "url" : "https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/generator/RUSTSEC-2020-0151.md"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2020-0151.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-362" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-18T20:33:21Z",
    "nvd_published_at" : "2021-08-08T06:15:00Z"
  }
}