CVE-2020-35893: Simple slab Off-by-one Error Vulnerability

HIGH
Advisory Identifier: GHSA-hqc8-j86x-2764
Share
CVSS 7.5
CWE-193
Published
Advisory Summary

CVE-2020-35893 is a HIGH (CVSS 7.5) off-by-one error vulnerability (CWE-193: Off-by-one Error) affecting Simple slab libraries in the crates.io ecosystem. The issue involves off-by-one error in simple-slab. Remediation is available by upgrading affected packages to version 0.3.3.

CVE-2020-35893 at a Glance

CVE Identifier CVE-2020-35893
GHSA Identifier GHSA-hqc8-j86x-2764
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-193: Off-by-one Error
Affected Product Simple slab
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:N/I:N/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 None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2020-35893

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

simple-slab fixed: 0.3.3 
Upgrade simple-slab to 0.3.3
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 simple-slab

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-35893, inspect your project dependencies for Simple slab:

inspect dependencies for simple-slab

Analyze the terminal output to locate any version of Simple slab in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.3.3), 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-193: Off-by-one Error, where a product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value. In Simple slab, 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 simple-slab crate before 0.3.3 for Rust. remove() has an off-by-one error, causing memory leakage and a drop of uninitialized memory.

CVE-2020-35893 Affected Simple slab Versions

1 component(s)
Fixed Versions:
0.3.3
Product / Package Ecosystem Affected Versions Fixed Version
simple-slab
 crates.io
< 0.3.3
0.3.3

References

NVD — CVE-2020-35893 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-35893
Simple slab Source Repository REPOSITORY
https://github.com/nathansizemore/simple-slab/issues/2
Security Fix Commit FIX COMMIT
https://github.com/nathansizemore/simple-slab/commit/5e0524c1db836e2192e1cd818848d96937c0b587
Simple slab Source Repository REPOSITORY
https://github.com/nathansizemore/simple-slab
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2020-0039.html

Frequently Asked Questions

What is CVE-2020-35893?
CVE-2020-35893 is a security vulnerability in Simple slab involving Off-by-one error in simple-slab under CWE-193: Off-by-one Error.
Which Simple slab versions are affected?
Affected versions include releases prior to 0.3.3 across affected packages: simple-slab.
What version fixes CVE-2020-35893?
Upgrading to 0.3.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is simple-slab affected?
Yes, simple-slab is affected in releases prior to 0.3.3. Upgrade your dependency to 0.3.3 or later.
What is the CVSS score of CVE-2020-35893?
CVE-2020-35893 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:N/I:N/A:H.
What CWE is associated with CVE-2020-35893?
CVE-2020-35893 is classified under CWE-193: Off-by-one Error (A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.).
How can I check crates.io dependencies for CVE-2020-35893?
Run the dependency tree command: 'inspect dependencies for simple-slab'. 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-hqc8-j86x-2764",
  "modified" : "2021-08-19T21:06:47Z",
  "published" : "2021-08-25T20:48:33Z",
  "aliases" : [ "CVE-2020-35893" ],
  "summary" : "Off-by-one error in simple-slab",
  "details" : "An issue was discovered in the simple-slab crate before 0.3.3 for Rust. remove() has an off-by-one error, causing memory leakage and a drop of uninitialized memory.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "simple-slab"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.3.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-35893"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nathansizemore/simple-slab/issues/2"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nathansizemore/simple-slab/commit/5e0524c1db836e2192e1cd818848d96937c0b587"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/nathansizemore/simple-slab"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2020-0039.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-193" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-19T21:06:47Z",
    "nvd_published_at" : null
  }
}