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@hoppscotch/cli affected by Sandbox Escape in @hoppscotch/js-sandbox leads to RCE

High severity GitHub Reviewed Published Apr 22, 2024 in hoppscotch/hoppscotch • Updated May 8, 2024

Package

npm @hoppscotch/cli (npm)

Affected versions

>= 0.5.0, < 0.8.0

Patched versions

0.8.0

Description

Observations

The Hoppscotch desktop app takes multiple precautions to be secure against arbitrary JavaScript and system command execution. It does not render user-controlled HTML or Markdown, uses Tauri instead of Electron, and sandboxes pre-request scripts with a simple yet secure implementation using web workers.

Unfortunately, web workers are not available in a pure Node.js application like Hoppscotch CLI. That is why the @hoppscotch/js-sandbox package also provides a Javascript sandbox that uses the Node.js vm module. However, the vm module is not safe for sandboxing untrusted Javascript code, as stated in the documentation. This is because code inside the vm context can break out if it can get a hold of any reference to an object created outside of the vm.

In the case of @hoppscotch/js-sandbox, multiple references to external objects are passed into the vm context to allow pre-request scripts interactions with environment variables and more. But this also allows the pre-request script to escape the sandbox.
packages/hoppscotch-js-sandbox/src/pre-request/node-vm/index.ts

const { pw, updatedEnvs } = getPreRequestScriptMethods(envs)

// Expose pw to the context
context.pw = pw
context.atob = atob
context.btoa = btoa

// Run the pre-request script in the provided context
runInContext(preRequestScript, context)

Exploitation

An attacker can use the exposed pw object reference to escape the sandbox and execute arbitrary system commands using the child_process Node.js module. This PoC pre-request script executes the id > /tmp/pwnd system command as soon as a request is sent.

outside = pw.constructor.constructor('return this')()
outside.process.mainModule.require('child_process').execSync('id > /tmp/pwnd')

An attacker who wants to run arbitrary code on the machine of a victim can create a Hoppscotch collection containing a request with a malicious pre-request script and share it with a victim, using the JSON export feature. The victim then has to run the collection with the Hoppscotch CLI. Then the malicious pre-request script executes.

Impact

This attack gives an attacker arbitrary command execution on the machine of a victim Hoppscotch CLI user. For the attack to succeed, an attacker has to lure the victim into downloading a malicious Hoppscotch collection and running it with the Hoppscotch CLI.

This issue does not impact Hoppscotch Web or Desktop, as they use the safe web worker sandboxing approach.

Recommendations

Hoppscotch CLI and other tools that rely on @hoppscotch/js-sandbox but don't have access to a browser cannot use the web worker sandbox. For these, you can look into other safe JavaScript sandboxing libraries. We think that isolated-vm looks promising. We discourage the use of vm2, which is deprecated because it has arbitrary bypasses. Alternatively, you can introduce an --enable-scripting flag for the CLI and disable scripting by default. Or you can change the threat model and educate users that they should not run untrusted collections as it can lead to RCE.

Differences from existing CVEs

References

@AndrewBastin AndrewBastin published to hoppscotch/hoppscotch Apr 22, 2024
Published to the GitHub Advisory Database Apr 22, 2024
Reviewed Apr 22, 2024
Published by the National Vulnerability Database May 8, 2024
Last updated May 8, 2024

Severity

High

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
High
Privileges required
None
User interaction
Required
Scope
Changed
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:H/PR:N/UI:R/S:C/C:H/I:H/A:H

EPSS score

0.043%
(10th percentile)

Weaknesses

CVE ID

CVE-2024-34347

GHSA ID

GHSA-qmmm-73r2-f8xr

Source code

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