CVE-2020-7674: Access policy Improper Input Validation Vulnerability

CRITICAL
Advisory Identifier: GHSA-fw2f-7f87-5r6c
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CVSS 9.8
CWE-94
Published
Advisory Summary

CVE-2020-7674 is a CRITICAL (CVSS 9.8) improper input validation vulnerability (CWE-94: Improper Control of Generation of Code ('Code Injection')) affecting Access policy libraries in the npm ecosystem. The issue involves improper input validation in access-policy. Remediation is available in the latest vendor maintenance releases.

CVE-2020-7674 at a Glance

CVE Identifier CVE-2020-7674
GHSA Identifier GHSA-fw2f-7f87-5r6c
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-94: Improper Control of Generation of Code ('Code Injection')
Affected Product Access policy
Package Ecosystem npm
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-2020-7674

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

access-policy fixed: Latest secure release 
npm install access-policy@Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls access-policy

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2020-7674, inspect your project dependencies using npm:

npm ls access-policy

Analyze the terminal output to locate any version of Access policy in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The npm ls access-policy command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-94: Improper Control of Generation of Code ('Code Injection'), where the product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. In Access policy, 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

access-policy through 3.1.0 is vulnerable to Arbitrary Code Execution. User input provided to the `template` function is executed by the `eval` function resulting in code execution.

CVE-2020-7674 Affected Access policy Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
access-policy
npm/access-policy
npm
≤ 3.1.0

References

NVD — CVE-2020-7674 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-7674
snyk.io/vuln/snyk-js-access... WEB
https://snyk.io/vuln/SNYK-JS-ACCESSPOLICY-571490

Frequently Asked Questions

What is CVE-2020-7674?
CVE-2020-7674 is a security vulnerability in Access policy involving Improper Input Validation in access-policy under CWE-94: Improper Control of Generation of Code ('Code Injection').
Which Access policy versions are affected?
Affected versions include releases prior to current release patches across affected packages: access-policy.
What version fixes CVE-2020-7674?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is access-policy affected?
Yes, access-policy is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2020-7674?
CVE-2020-7674 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-2020-7674?
CVE-2020-7674 is classified under CWE-94: Improper Control of Generation of Code ('Code Injection') (The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.).
How can I check npm dependencies for CVE-2020-7674?
Run the dependency tree command: 'npm ls access-policy'. 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-fw2f-7f87-5r6c",
  "modified" : "2021-07-29T18:14:19Z",
  "published" : "2021-05-17T21:00:29Z",
  "aliases" : [ "CVE-2020-7674" ],
  "summary" : "Improper Input Validation in access-policy",
  "details" : "access-policy through 3.1.0 is vulnerable to Arbitrary Code Execution. User input provided to the `template` function is executed by the `eval` function resulting in code execution.",
  "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" : "npm",
      "name" : "access-policy"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "3.1.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-7674"
  }, {
    "type" : "WEB",
    "url" : "https://snyk.io/vuln/SNYK-JS-ACCESSPOLICY-571490"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-94" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-05-13T17:15:59Z",
    "nvd_published_at" : "2020-06-10T16:15:00Z"
  }
}