CVE-2020-35927: Thex Data Races Vulnerability

MODERATE
Advisory Identifier: GHSA-j42v-6wpm-r847
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CVSS 5.5
CWE-662
Published
Advisory Summary

CVE-2020-35927 is a MODERATE (CVSS 5.5) data races vulnerability (CWE-662: Improper Synchronization) affecting Thex libraries in the crates.io ecosystem. The issue involves data races in thex. Remediation is available in the latest vendor maintenance releases.

CVE-2020-35927 at a Glance

CVE Identifier CVE-2020-35927
GHSA Identifier GHSA-j42v-6wpm-r847
Severity MODERATE
CVSS v3.1 Base Score 5.5
CWE Classification CWE-662: Improper Synchronization
Affected Product Thex
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 5.5

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

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
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-2020-35927

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

thex fixed: Latest secure release 
Upgrade thex to Latest secure release
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 thex

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-35927, inspect your project dependencies for Thex:

inspect dependencies for thex

Analyze the terminal output to locate any version of Thex in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), 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-662: Improper Synchronization, where the product utilizes multiple threads, processes, components, or systems to allow temporary access to a shared resource that can only be exclusive to one process at a time, but it does not properly synchronize these actions, which might cause simultaneous accesses of this resource by multiple threads or processes. In Thex, 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

An issue was discovered in the thex crate through 2020-12-08 for Rust. Thex<T> allows cross-thread data races of non-Send types.

CVE-2020-35927 Affected Thex Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
thex
 crates.io
≤ 0.1.0

References

NVD — CVE-2020-35927 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-35927
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2020-0090.html

Frequently Asked Questions

What is CVE-2020-35927?
CVE-2020-35927 is a security vulnerability in Thex involving Data races in thex under CWE-662: Improper Synchronization.
Which Thex versions are affected?
Affected versions include releases prior to current release patches across affected packages: thex.
What version fixes CVE-2020-35927?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is thex affected?
Yes, thex is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2020-35927?
CVE-2020-35927 has a CVSS v3.1 base score of 5.5 (MODERATE) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2020-35927?
CVE-2020-35927 is classified under CWE-662: Improper Synchronization (The product utilizes multiple threads, processes, components, or systems to allow temporary access to a shared resource that can only be exclusive to one process at a time, but it does not properly synchronize these actions, which might cause simultaneous accesses of this resource by multiple threads or processes.).
How can I check crates.io dependencies for CVE-2020-35927?
Run the dependency tree command: 'inspect dependencies for thex'. 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-j42v-6wpm-r847",
  "modified" : "2021-08-19T18:55:21Z",
  "published" : "2021-08-25T20:50:26Z",
  "aliases" : [ "CVE-2020-35927" ],
  "summary" : "Data races in thex",
  "details" : "An issue was discovered in the thex crate through 2020-12-08 for Rust. Thex<T> allows cross-thread data races of non-Send types.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "thex"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.1.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-35927"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2020-0090.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-662" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-19T18:55:21Z",
    "nvd_published_at" : null
  }
}