CVE-2020-35876: Rio Use After Free Vulnerability

CRITICAL
Advisory Identifier: GHSA-8rc5-mr4f-m243
Share
CVSS 9.8
CWE-772 CWE-416
Published
Advisory Summary

CVE-2020-35876 is a CRITICAL (CVSS 9.8) use after free vulnerability (CWE-772: Missing Release of Resource after Effective Lifetime) affecting Rio libraries in the crates.io ecosystem. The issue involves use after free in rio. Remediation is available in the latest vendor maintenance releases.

CVE-2020-35876 at a Glance

CVE Identifier CVE-2020-35876
GHSA Identifier GHSA-8rc5-mr4f-m243
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-772: Missing Release of Resource after Effective Lifetime
Affected Product Rio
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-2020-35876

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

rio fixed: Latest secure release 
Upgrade rio 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 rio

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-35876, inspect your project dependencies for Rio:

inspect dependencies for rio

Analyze the terminal output to locate any version of Rio 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-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 Rio, 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 rio crate through 2020-05-11 for Rust. A struct can be leaked, allowing attackers to obtain sensitive information, cause a use-after-free, or cause a data race.

CVE-2020-35876 Affected Rio Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
rio
 crates.io
≤ 0.9.4

References

NVD — CVE-2020-35876 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-35876
Rio Source Repository REPOSITORY
https://github.com/spacejam/rio/issues/11
Rio Source Repository REPOSITORY
https://github.com/spacejam/rio/pull/31
Rio Source Repository REPOSITORY
https://github.com/spacejam/rio
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2020-0021.html

Frequently Asked Questions

What is CVE-2020-35876?
CVE-2020-35876 is a security vulnerability in Rio involving Use after free in rio under CWE-772: Missing Release of Resource after Effective Lifetime.
Which Rio versions are affected?
Affected versions include releases prior to current release patches across affected packages: rio.
What version fixes CVE-2020-35876?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is rio affected?
Yes, rio 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-2020-35876?
CVE-2020-35876 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-2020-35876?
CVE-2020-35876 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-2020-35876?
Run the dependency tree command: 'inspect dependencies for rio'. 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-8rc5-mr4f-m243",
  "modified" : "2021-08-19T21:18:55Z",
  "published" : "2021-08-25T20:46:57Z",
  "aliases" : [ "CVE-2020-35876" ],
  "summary" : "Use after free in rio",
  "details" : "An issue was discovered in the rio crate through 2020-05-11 for Rust. A struct can be leaked, allowing attackers to obtain sensitive information, cause a use-after-free, or cause a data race.",
  "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" : "rio"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.9.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-35876"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/spacejam/rio/issues/11"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/spacejam/rio/pull/31"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/spacejam/rio"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2020-0021.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-416", "CWE-772" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-19T21:18:55Z",
    "nvd_published_at" : null
  }
}