CVE-2021-30454: Outer cgi Uninitialized Memory Access Vulnerability

CRITICAL
Advisory Identifier: GHSA-6vmq-jh76-hq43
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CVSS 9.8
CWE-119
Published
Advisory Summary

CVE-2021-30454 is a CRITICAL (CVSS 9.8) uninitialized memory access vulnerability (CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer) affecting Outer cgi libraries in the crates.io ecosystem. The issue involves uninitialized memory access in outer_cgi. Remediation is available by upgrading affected packages to version 0.2.1.

CVE-2021-30454 at a Glance

CVE Identifier CVE-2021-30454
GHSA Identifier GHSA-6vmq-jh76-hq43
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer
Affected Product Outer cgi
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-2021-30454

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

outer_cgi fixed: 0.2.1 
Upgrade outer_cgi to 0.2.1
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 outer_cgi

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-30454, inspect your project dependencies for Outer cgi:

inspect dependencies for outer_cgi

Analyze the terminal output to locate any version of Outer cgi in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.2.1), 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-119: Improper Restriction of Operations within the Bounds of a Memory Buffer, where the product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. this may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data. In Outer cgi, 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 outer_cgi crate before 0.2.1 for Rust. A user-provided Read instance receives an uninitialized memory buffer from KeyValueReader.

CVE-2021-30454 Affected Outer cgi Versions

1 component(s)
Fixed Versions:
0.2.1
Product / Package Ecosystem Affected Versions Fixed Version
outer_cgi
 crates.io
< 0.2.1
0.2.1

References

NVD — CVE-2021-30454 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-30454
Outer cgi Source Repository REPOSITORY
https://github.com/SolraBizna/outer_cgi/issues/1
Security Fix Commit FIX COMMIT
https://github.com/SolraBizna/outer_cgi/commit/dd59b3066e616a08e756f72de8dc3ab11b7036c4
Outer cgi Source Repository REPOSITORY
https://github.com/SolraBizna/outer_cgi
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2021-0051.html

Frequently Asked Questions

What is CVE-2021-30454?
CVE-2021-30454 is a security vulnerability in Outer cgi involving Uninitialized memory access in outer_cgi under CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer.
Which Outer cgi versions are affected?
Affected versions include releases prior to 0.2.1 across affected packages: outer_cgi.
What version fixes CVE-2021-30454?
Upgrading to 0.2.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is outer_cgi affected?
Yes, outer_cgi is affected in releases prior to 0.2.1. Upgrade your dependency to 0.2.1 or later.
What is the CVSS score of CVE-2021-30454?
CVE-2021-30454 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-2021-30454?
CVE-2021-30454 is classified under CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer (The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.).
How can I check crates.io dependencies for CVE-2021-30454?
Run the dependency tree command: 'inspect dependencies for outer_cgi'. 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-6vmq-jh76-hq43",
  "modified" : "2022-06-14T22:22:47Z",
  "published" : "2021-08-25T20:55:25Z",
  "aliases" : [ "CVE-2021-30454" ],
  "summary" : "Uninitialized memory access in outer_cgi",
  "details" : "An issue was discovered in the outer_cgi crate before 0.2.1 for Rust. A user-provided Read instance receives an uninitialized memory buffer from KeyValueReader.",
  "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" : "outer_cgi"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.2.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-30454"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/SolraBizna/outer_cgi/issues/1"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/SolraBizna/outer_cgi/commit/dd59b3066e616a08e756f72de8dc3ab11b7036c4"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/SolraBizna/outer_cgi"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2021-0051.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-119" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-19T17:03:35Z",
    "nvd_published_at" : null
  }
}