CVE-2020-35859: Lucet runtime internals Out Of Bounds Access Vulnerability

CRITICAL
Advisory Identifier: GHSA-3933-wvjf-pcvc
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CVSS 9.1
CWE-125 CWE-787
Published
Advisory Summary

CVE-2020-35859 is a CRITICAL (CVSS 9.1) out of bounds access vulnerability (CWE-125: Out-of-bounds Read) affecting Lucet runtime internals libraries in the crates.io ecosystem. The issue involves out of bounds access in lucet-runtime-internals. Remediation is available by upgrading affected packages to version 0.4.3, 0.5.1.

CVE-2020-35859 at a Glance

CVE Identifier CVE-2020-35859
GHSA Identifier GHSA-3933-wvjf-pcvc
Severity CRITICAL
CVSS v3.1 Base Score 9.1
CWE Classification CWE-125: Out-of-bounds Read
Affected Product Lucet runtime internals
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 9.1

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: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 High (C:H)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2020-35859

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

lucet-runtime-internals fixed: 0.4.3 
Upgrade lucet-runtime-internals to 0.4.3
lucet-runtime-internals fixed: 0.5.1 
Upgrade lucet-runtime-internals to 0.5.1
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 lucet-runtime-internals

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-35859, inspect your project dependencies for Lucet runtime internals:

inspect dependencies for lucet-runtime-internals

Analyze the terminal output to locate any version of Lucet runtime internals in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.4.3), 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-125: Out-of-bounds Read, where the product reads data past the end, or before the beginning, of the intended buffer. In Lucet runtime internals, 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 embedding using affected versions of lucet-runtime configured to use non-default Wasm globals sizes of more than 4KiB, or compiled in debug mode without optimizations, could leak data from the signal handler stack to guest programs. This can potentially cause data from the embedding host to leak to guest programs or cause corruption of guest program memory. This flaw was resolved by correcting the sigstack allocation logic.

CVE-2020-35859 Affected Lucet runtime internals Versions

2 component(s)
Fixed Versions:
0.4.30.5.1
Product / Package Ecosystem Affected Versions Fixed Version
lucet-runtime-internals
 crates.io
< 0.4.3
0.4.3
lucet-runtime-internals
 crates.io
≥ 0.5.0
< 0.5.1
0.5.1

References

NVD — CVE-2020-35859 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-35859
Lucet runtime internals Source Repository REPOSITORY
https://github.com/bytecodealliance/lucet/pull/401
Lucet runtime internals Source Repository REPOSITORY
https://github.com/fastly/lucet
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2020-0004.html

Frequently Asked Questions

What is CVE-2020-35859?
CVE-2020-35859 is a security vulnerability in Lucet runtime internals involving Out of bounds access in lucet-runtime-internals under CWE-125: Out-of-bounds Read.
Which Lucet runtime internals versions are affected?
Affected versions include releases prior to 0.4.3, 0.5.1 across affected packages: lucet-runtime-internals.
What version fixes CVE-2020-35859?
Upgrading to 0.4.3, 0.5.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is lucet-runtime-internals affected?
Yes, lucet-runtime-internals is affected in releases prior to 0.4.3, 0.5.1. Upgrade your dependency to 0.4.3, 0.5.1 or later.
What is the CVSS score of CVE-2020-35859?
CVE-2020-35859 has a CVSS v3.1 base score of 9.1 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.
What CWE is associated with CVE-2020-35859?
CVE-2020-35859 is classified under CWE-125: Out-of-bounds Read (The product reads data past the end, or before the beginning, of the intended buffer.).
How can I check crates.io dependencies for CVE-2020-35859?
Run the dependency tree command: 'inspect dependencies for lucet-runtime-internals'. 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-3933-wvjf-pcvc",
  "modified" : "2023-06-13T20:06:37Z",
  "published" : "2021-08-25T20:46:16Z",
  "aliases" : [ "CVE-2020-35859" ],
  "summary" : "Out of bounds access in lucet-runtime-internals",
  "details" : "An embedding using affected versions of lucet-runtime configured to use non-default Wasm globals sizes of more than 4KiB, or compiled in debug mode without optimizations, could leak data from the signal handler stack to guest programs. This can potentially cause data from the embedding host to leak to guest programs or cause corruption of guest program memory. This flaw was resolved by correcting the sigstack allocation logic.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "lucet-runtime-internals"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.4.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "lucet-runtime-internals"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.5.0"
      }, {
        "fixed" : "0.5.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-35859"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/bytecodealliance/lucet/pull/401"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/fastly/lucet"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2020-0004.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-125", "CWE-787" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-19T21:19:58Z",
    "nvd_published_at" : "2020-12-31T10:15:14Z"
  }
}