CVE-2020-35858: Prost Out Of Bounds Write Vulnerability

CRITICAL
Advisory Identifier: GHSA-gv73-9mwv-fwgq
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CVSS 9.8
CWE-787
Published
Advisory Summary

CVE-2020-35858 is a CRITICAL (CVSS 9.8) out of bounds write vulnerability (CWE-787: Out-of-bounds Write) affecting Prost libraries in the crates.io ecosystem. The issue involves out of bounds write in prost. Remediation is available by upgrading affected packages to version 0.6.1.

CVE-2020-35858 at a Glance

CVE Identifier CVE-2020-35858
GHSA Identifier GHSA-gv73-9mwv-fwgq
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-787: Out-of-bounds Write
Affected Product Prost
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-2020-35858

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

prost fixed: 0.6.1 
Upgrade prost to 0.6.1
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 prost

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-35858, inspect your project dependencies for Prost:

inspect dependencies for prost

Analyze the terminal output to locate any version of Prost in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.6.1), 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 Prost, 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 this crate contained a bug in which decoding untrusted input could overflow the stack. On architectures with stack probes (like x86), this can be used for denial of service attacks, while on architectures without stack probes (like ARM) overflowing the stack is unsound and can result in potential memory corruption (or even RCE).

CVE-2020-35858 Affected Prost Versions

1 component(s)
Fixed Versions:
0.6.1
Product / Package Ecosystem Affected Versions Fixed Version
prost
 crates.io
< 0.6.1
0.6.1

References

NVD — CVE-2020-35858 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-35858
Prost Source Repository REPOSITORY
https://github.com/danburkert/prost/issues/267
Security Fix Commit FIX COMMIT
https://github.com/danburkert/prost/commit/04091d3e745c27590a5f1b7f581793e4159486b5
Prost Source Repository REPOSITORY
https://github.com/danburkert/prost
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2020-0002.html

Frequently Asked Questions

What is CVE-2020-35858?
CVE-2020-35858 is a security vulnerability in Prost involving Out of bounds write in prost under CWE-787: Out-of-bounds Write.
Which Prost versions are affected?
Affected versions include releases prior to 0.6.1 across affected packages: prost.
What version fixes CVE-2020-35858?
Upgrading to 0.6.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is prost affected?
Yes, prost is affected in releases prior to 0.6.1. Upgrade your dependency to 0.6.1 or later.
What is the CVSS score of CVE-2020-35858?
CVE-2020-35858 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-2020-35858?
CVE-2020-35858 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-2020-35858?
Run the dependency tree command: 'inspect dependencies for prost'. 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-gv73-9mwv-fwgq",
  "modified" : "2023-06-13T20:33:10Z",
  "published" : "2021-08-25T20:46:11Z",
  "aliases" : [ "CVE-2020-35858" ],
  "summary" : "Out of bounds write in prost",
  "details" : "Affected versions of this crate contained a bug in which decoding untrusted input could overflow the stack. On architectures with stack probes (like x86), this can be used for denial of service attacks, while on architectures without stack probes (like ARM) overflowing the stack is unsound and can result in potential memory corruption (or even RCE).",
  "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" : "prost"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.6.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-35858"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/danburkert/prost/issues/267"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/danburkert/prost/commit/04091d3e745c27590a5f1b7f581793e4159486b5"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/danburkert/prost"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2020-0002.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-787" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-19T21:20:08Z",
    "nvd_published_at" : null
  }
}