CVE-2020-36469: Appendix Data Races Vulnerability

MODERATE
Advisory Identifier: GHSA-fvhr-7j8m-3cvc
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CVSS 5.9
CWE-362
Published
Advisory Summary

CVE-2020-36469 is a MODERATE (CVSS 5.9) data races vulnerability (CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')) affecting Appendix libraries in the crates.io ecosystem. The issue involves data races in appendix. Remediation is available in the latest vendor maintenance releases.

CVE-2020-36469 at a Glance

CVE Identifier CVE-2020-36469
GHSA Identifier GHSA-fvhr-7j8m-3cvc
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 Appendix
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-2020-36469

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

appendix fixed: Latest secure release 
Upgrade appendix 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 appendix

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-36469, inspect your project dependencies for Appendix:

inspect dependencies for appendix

Analyze the terminal output to locate any version of Appendix 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-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 Appendix, 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 `appendix` crate implements a key-value mapping data structure called `Index<K, V>` that is stored on disk. The crate allows for any type to inhabit the generic `K` and `V` type parameters and implements Send and Sync for them unconditionally. Using a type that is not marked as `Send` or `Sync` with `Index` can allow it to be used across multiple threads leading to data races. Additionally using reference types for the keys or values will lead to the segmentation faults in the crate's code.

CVE-2020-36469 Affected Appendix Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
appendix
 crates.io
≤ 0.2.0

References

NVD — CVE-2020-36469 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-36469
Appendix Source Repository REPOSITORY
https://github.com/krl/appendix/issues/6
Appendix Source Repository REPOSITORY
https://github.com/krl/appendix
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2020-0149.html

Frequently Asked Questions

What is CVE-2020-36469?
CVE-2020-36469 is a security vulnerability in Appendix involving Data races in appendix under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition').
Which Appendix versions are affected?
Affected versions include releases prior to current release patches across affected packages: appendix.
What version fixes CVE-2020-36469?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is appendix affected?
Yes, appendix 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-2020-36469?
CVE-2020-36469 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-2020-36469?
CVE-2020-36469 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-2020-36469?
Run the dependency tree command: 'inspect dependencies for appendix'. 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-fvhr-7j8m-3cvc",
  "modified" : "2021-08-24T19:08:25Z",
  "published" : "2021-08-25T20:57:02Z",
  "aliases" : [ "CVE-2020-36469" ],
  "summary" : "Data races in appendix",
  "details" : "The `appendix` crate implements a key-value mapping data structure called\n`Index<K, V>` that is stored on disk. The crate allows for any type to inhabit\nthe generic `K` and `V` type parameters and implements Send and Sync for them\nunconditionally.\n\nUsing a type that is not marked as `Send` or `Sync` with `Index` can allow it\nto be used across multiple threads leading to data races. Additionally using\nreference types for the keys or values will lead to the segmentation faults\nin the crate's code.",
  "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" : "appendix"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.2.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-36469"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/krl/appendix/issues/6"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/krl/appendix"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2020-0149.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-362" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-18T20:35:37Z",
    "nvd_published_at" : "2021-08-08T06:15:00Z"
  }
}