Description (CNA)
vm2 is a sandbox for running untrusted JavaScript. In vm2 versions up to and including 3.11.3, the defaultSandboxPrepareStackTrace function in lib/setup-sandbox.js builds its output array using prototype-walking index assignment (lines[lines.length] = value) rather than a prototype-bypassing define-property primitive. Because this bridge-internal array is allocated in the sandbox realm, code inside the sandbox can install an accessor on Array.prototype for the relevant index; the accessor is then invoked whenever the sandbox reads error.stack (or otherwise triggers Error.prepareStackTrace), allowing sandbox code to observe and intercept each stack-trace line written by the bridge. The same pattern is used in the error-handling (catch) branch. The values written are formatted strings only, so the practical impact is limited to an information side channel and a violation of vm2's bridge-container defense invariant rather than a sandbox escape; the vendor rates the issue Low. The issue is fixed in vm2 3.11.4, which installs each entry as an own data property via Reflect.defineProperty.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| patriksimek / vm2 | affected 0 before 3.11.4; unaffected 3.11.4 |
CWE
CWE-693
References
- https://github.com/patriksimek/vm2/security/advisories/GHSA-q3fm-4wcw-g57x
- https://www.vulncheck.com/advisories/vm2-before-3.11.4-defense-invariant-violation-via-setup-sandbox-js
ADP enrichment
No English description supplied.