CVE-2021-28031: Scratchpad Move_elements Can Double-free Objects On Vulnerability

CRITICAL
Advisory Identifier: GHSA-3qm2-rfqw-fmrw
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CVSS 9.8
CWE-415
Published
Advisory Summary

CVE-2021-28031 is a CRITICAL (CVSS 9.8) move_elements can double-free objects on vulnerability (CWE-415: Double Free) affecting Scratchpad libraries in the crates.io ecosystem. The issue involves move_elements can double-free objects on panic. Remediation is available by upgrading affected packages to version 1.3.1.

CVE-2021-28031 at a Glance

CVE Identifier CVE-2021-28031
GHSA Identifier GHSA-3qm2-rfqw-fmrw
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-415: Double Free
Affected Product Scratchpad
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-2021-28031

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

scratchpad fixed: 1.3.1 
Upgrade scratchpad to 1.3.1
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 scratchpad

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-28031, inspect your project dependencies for Scratchpad:

inspect dependencies for scratchpad

Analyze the terminal output to locate any version of Scratchpad in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.3.1), 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-415: Double Free, where the product calls free() twice on the same memory address. In Scratchpad, 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

Affected versions of scratchpad used ptr::read to read elements while calling a user provided function f on them. Since the pointer read duplicates ownership, a panic inside the user provided f function could cause a double free when unwinding. The flaw was fixed in commit `891561bea` by removing the unsafe block and using a plain iterator.

CVE-2021-28031 Affected Scratchpad Versions

1 component(s)
Fixed Versions:
1.3.1
Product / Package Ecosystem Affected Versions Fixed Version
scratchpad
 crates.io
< 1.3.1
1.3.1

References

NVD — CVE-2021-28031 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-28031
Scratchpad Source Repository REPOSITORY
https://github.com/okready/scratchpad/issues/1
Security Fix Commit FIX COMMIT
https://github.com/okready/scratchpad/commit/891561bea
Scratchpad Source Repository REPOSITORY
https://github.com/okready/scratchpad
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2021-0030.html

Frequently Asked Questions

What is CVE-2021-28031?
CVE-2021-28031 is a security vulnerability in Scratchpad involving move_elements can double-free objects on panic under CWE-415: Double Free.
Which Scratchpad versions are affected?
Affected versions include releases prior to 1.3.1 across affected packages: scratchpad.
What version fixes CVE-2021-28031?
Upgrading to 1.3.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is scratchpad affected?
Yes, scratchpad is affected in releases prior to 1.3.1. Upgrade your dependency to 1.3.1 or later.
What is the CVSS score of CVE-2021-28031?
CVE-2021-28031 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-2021-28031?
CVE-2021-28031 is classified under CWE-415: Double Free (The product calls free() twice on the same memory address.).
How can I check crates.io dependencies for CVE-2021-28031?
Run the dependency tree command: 'inspect dependencies for scratchpad'. 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-3qm2-rfqw-fmrw",
  "modified" : "2023-06-13T20:40:29Z",
  "published" : "2022-05-24T17:43:48Z",
  "aliases" : [ "CVE-2021-28031" ],
  "summary" : "move_elements can double-free objects on panic",
  "details" : "Affected versions of scratchpad used ptr::read to read elements while calling a user provided function f on them. Since the pointer read duplicates ownership, a panic inside the user provided f function could cause a double free when unwinding.\n\nThe flaw was fixed in commit `891561bea` by removing the unsafe block and using a plain iterator.",
  "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" : "scratchpad"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.3.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-28031"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/okready/scratchpad/issues/1"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/okready/scratchpad/commit/891561bea"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/okready/scratchpad"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2021-0030.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-415" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-06-17T00:23:59Z",
    "nvd_published_at" : "2021-03-05T09:15:00Z"
  }
}