CVE-2020-35895: Stack Out-of-bounds Write Vulnerability

CRITICAL
Advisory Identifier: GHSA-h45v-vgvp-3h5v
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CVSS 9.8
CWE-787
Published
Advisory Summary

CVE-2020-35895 is a CRITICAL (CVSS 9.8) out-of-bounds write vulnerability (CWE-787: Out-of-bounds Write) affecting Stack libraries in the crates.io ecosystem. The issue involves out-of-bounds write in stack. Remediation is available by upgrading affected packages to version 0.3.1.

CVE-2020-35895 at a Glance

CVE Identifier CVE-2020-35895
GHSA Identifier GHSA-h45v-vgvp-3h5v
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-787: Out-of-bounds Write
Affected Product Stack
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-2020-35895

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

stack fixed: 0.3.1 
Upgrade stack to 0.3.1
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 stack

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-35895, inspect your project dependencies for Stack:

inspect dependencies for stack

Analyze the terminal output to locate any version of Stack in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.3.1), 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-787: Out-of-bounds Write, where the product writes data past the end, or before the beginning, of the intended buffer. In Stack, 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

ArrayVec::insert allows insertion of an element into the array object into the specified index. Due to a missing check on the upperbound of this index, it is possible to write out of bounds.

CVE-2020-35895 Affected Stack Versions

1 component(s)
Fixed Versions:
0.3.1
Product / Package Ecosystem Affected Versions Fixed Version
stack
 crates.io
< 0.3.1
0.3.1

References

NVD — CVE-2020-35895 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-35895
Stack Source Repository REPOSITORY
https://github.com/arcnmx/stack-rs/issues/4
Security Fix Commit FIX COMMIT
https://github.com/arcnmx/stack-rs/commit/369e55736f9bd29c37b1712afc2923f4028148c6
Stack Source Repository REPOSITORY
https://github.com/arcnmx/stack-rs
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2020-0042.html

Frequently Asked Questions

What is CVE-2020-35895?
CVE-2020-35895 is a security vulnerability in Stack involving Out-of-bounds write in stack under CWE-787: Out-of-bounds Write.
Which Stack versions are affected?
Affected versions include releases prior to 0.3.1 across affected packages: stack.
What version fixes CVE-2020-35895?
Upgrading to 0.3.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is stack affected?
Yes, stack is affected in releases prior to 0.3.1. Upgrade your dependency to 0.3.1 or later.
What is the CVSS score of CVE-2020-35895?
CVE-2020-35895 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-2020-35895?
CVE-2020-35895 is classified under CWE-787: Out-of-bounds Write (The product writes data past the end, or before the beginning, of the intended buffer.).
How can I check crates.io dependencies for CVE-2020-35895?
Run the dependency tree command: 'inspect dependencies for stack'. 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-h45v-vgvp-3h5v",
  "modified" : "2023-06-13T20:54:35Z",
  "published" : "2021-08-25T20:49:13Z",
  "aliases" : [ "CVE-2020-35895" ],
  "summary" : "Out-of-bounds write in stack",
  "details" : "ArrayVec::insert allows insertion of an element into the array object into the specified index. Due to a missing check on the upperbound of this index, it is possible to write out of bounds.",
  "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" : "stack"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.3.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-35895"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/arcnmx/stack-rs/issues/4"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/arcnmx/stack-rs/commit/369e55736f9bd29c37b1712afc2923f4028148c6"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/arcnmx/stack-rs"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2020-0042.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-787" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-19T20:53:42Z",
    "nvd_published_at" : "2020-12-31T10:15:00Z"
  }
}