CVE-2020-7710: Safe eval Sandbox Breakout / Arbitrary Code Vulnerability

CRITICAL
Advisory Identifier: GHSA-hrpq-r399-whgw
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CVSS 9.8
CWE-94
Published
Advisory Summary

CVE-2020-7710 is a CRITICAL (CVSS 9.8) sandbox breakout / arbitrary code vulnerability (CWE-94: Improper Control of Generation of Code ('Code Injection')) affecting Safe eval libraries in the npm ecosystem. The issue involves sandbox breakout / arbitrary code execution in safe-eval. Remediation is available in the latest vendor maintenance releases.

CVE-2020-7710 at a Glance

CVE Identifier CVE-2020-7710
GHSA Identifier GHSA-hrpq-r399-whgw
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-94: Improper Control of Generation of Code ('Code Injection')
Affected Product Safe eval
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-2020-7710

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

safe-eval fixed: Latest secure release 
npm install safe-eval@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 safe-eval

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2020-7710, inspect your project dependencies using npm:

npm ls safe-eval

Analyze the terminal output to locate any version of Safe eval 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 safe-eval 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 Safe eval, 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

All versions of `safe-eval` are vulnerable to Sandbox Escape leading to Remote Code Execution. The package fails to restrict access to the main context through Error objects. This may allow attackers to execute arbitrary code in the system. Evaluating the payload ```js (function (){ var ex = new Error ex.__proto__ = null ex.stack = { match: x => { return x.constructor.constructor("throw process.env")() } } return ex })() ``` prints the contents of `process.env`. ## Recommendation No fix is currently available. Consider using an alternative package until a fix is made available.

CVE-2020-7710 Affected Safe eval Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
safe-eval
npm/safe-eval
npm
≤ 0.4.1

References

NVD — CVE-2020-7710 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-7710
Safe eval Source Repository REPOSITORY
https://github.com/hacksparrow/safe-eval/issues/19
snyk.io/vuln/snyk-js-safeev... WEB
https://snyk.io/vuln/SNYK-JS-SAFEEVAL-608076
www.npmjs.com/advisories/1322 WEB
https://www.npmjs.com/advisories/1322

Frequently Asked Questions

What is CVE-2020-7710?
CVE-2020-7710 is a security vulnerability in Safe eval involving Sandbox Breakout / Arbitrary Code Execution in safe-eval under CWE-94: Improper Control of Generation of Code ('Code Injection').
Which Safe eval versions are affected?
Affected versions include releases prior to current release patches across affected packages: safe-eval.
What version fixes CVE-2020-7710?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is safe-eval affected?
Yes, safe-eval 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-2020-7710?
CVE-2020-7710 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-2020-7710?
CVE-2020-7710 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-2020-7710?
Run the dependency tree command: 'npm ls safe-eval'. 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-hrpq-r399-whgw",
  "modified" : "2023-09-11T23:01:24Z",
  "published" : "2020-08-25T23:40:53Z",
  "aliases" : [ "CVE-2020-7710" ],
  "summary" : "Sandbox Breakout / Arbitrary Code Execution in safe-eval",
  "details" : "All versions of `safe-eval` are vulnerable to Sandbox Escape leading to Remote Code Execution. The package fails to restrict access to the main context through Error objects. This may allow attackers to execute arbitrary code in the system. \n\nEvaluating the payload \n```js\n(function (){\n  var ex = new Error\n  ex.__proto__ = null\n  ex.stack = {\n    match: x => {\n      return x.constructor.constructor(\"throw process.env\")()\n    }\n  }\n  return ex\n})()\n``` \n\nprints the contents of `process.env`.\n\n\n## Recommendation\n\nNo fix is currently available. Consider using an alternative package until a fix is made available.",
  "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" : "safe-eval"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.4.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-7710"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/hacksparrow/safe-eval/issues/19"
  }, {
    "type" : "WEB",
    "url" : "https://snyk.io/vuln/SNYK-JS-SAFEEVAL-608076"
  }, {
    "type" : "WEB",
    "url" : "https://www.npmjs.com/advisories/1322"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-94" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-08-25T21:20:22Z",
    "nvd_published_at" : "2020-08-21T10:15:00Z"
  }
}