CVE-2021-31919: Rkyv Use Of Uninitialized Buffer Vulnerability

HIGH
Advisory Identifier: GHSA-w5cr-frph-hw7f
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CVSS 7.5
CWE-772 CWE-908
Published
Advisory Summary

CVE-2021-31919 is a HIGH (CVSS 7.5) use of uninitialized buffer vulnerability (CWE-772: Missing Release of Resource after Effective Lifetime) affecting Rkyv libraries in the crates.io ecosystem. The issue involves use of uninitialized buffer in rkyv. Remediation is available by upgrading affected packages to version 0.6.0.

CVE-2021-31919 at a Glance

CVE Identifier CVE-2021-31919
GHSA Identifier GHSA-w5cr-frph-hw7f
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-772: Missing Release of Resource after Effective Lifetime
Affected Product Rkyv
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 7.5

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:N/A:N).

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 None (I:N)
Availability None (A:N)

How to Fix CVE-2021-31919

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

rkyv fixed: 0.6.0 
Upgrade rkyv to 0.6.0
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 rkyv

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-31919, inspect your project dependencies for Rkyv:

inspect dependencies for rkyv

Analyze the terminal output to locate any version of Rkyv in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.6.0), 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-772: Missing Release of Resource after Effective Lifetime, where the product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed. In Rkyv, 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 rkyv crate before 0.6.0 for Rust. When an archive is created via serialization, the archive content may contain uninitialized values of certain parts of a struct.

CVE-2021-31919 Affected Rkyv Versions

1 component(s)
Fixed Versions:
0.6.0
Product / Package Ecosystem Affected Versions Fixed Version
rkyv
 crates.io
< 0.6.0
0.6.0

References

NVD — CVE-2021-31919 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-31919
Rkyv Source Repository REPOSITORY
https://github.com/djkoloski/rkyv/issues/113
Security Fix Commit FIX COMMIT
https://github.com/djkoloski/rkyv/commit/9c65ae9c2c67dd949b5c3aba9b8eba6da802ab7e
Security Fix Commit FIX COMMIT
https://github.com/djkoloski/rkyv/commit/f141b560523a20557db6540576d153010bd18712
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2021-0054.html

Frequently Asked Questions

What is CVE-2021-31919?
CVE-2021-31919 is a security vulnerability in Rkyv involving Use of uninitialized buffer in rkyv under CWE-772: Missing Release of Resource after Effective Lifetime.
Which Rkyv versions are affected?
Affected versions include releases prior to 0.6.0 across affected packages: rkyv.
What version fixes CVE-2021-31919?
Upgrading to 0.6.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is rkyv affected?
Yes, rkyv is affected in releases prior to 0.6.0. Upgrade your dependency to 0.6.0 or later.
What is the CVSS score of CVE-2021-31919?
CVE-2021-31919 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2021-31919?
CVE-2021-31919 is classified under CWE-772: Missing Release of Resource after Effective Lifetime (The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.).
How can I check crates.io dependencies for CVE-2021-31919?
Run the dependency tree command: 'inspect dependencies for rkyv'. 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-w5cr-frph-hw7f",
  "modified" : "2021-05-25T20:52:53Z",
  "published" : "2021-08-25T21:01:50Z",
  "aliases" : [ "CVE-2021-31919" ],
  "summary" : "Use of uninitialized buffer in rkyv",
  "details" : "An issue was discovered in the rkyv crate before 0.6.0 for Rust. When an archive is created via serialization, the archive content may contain uninitialized values of certain parts of a struct.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "rkyv"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.6.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-31919"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/djkoloski/rkyv/issues/113"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/djkoloski/rkyv/commit/9c65ae9c2c67dd949b5c3aba9b8eba6da802ab7e"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/djkoloski/rkyv/commit/f141b560523a20557db6540576d153010bd18712"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2021-0054.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-772", "CWE-908" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-05-25T20:52:53Z",
    "nvd_published_at" : "2021-04-30T03:15:00Z"
  }
}