CVE-2021-23594: Prototype Pollution in realms-shim
9.8
CVSS Score
3.1
Basic Information
CVE ID
GHSA ID
EPSS Score
0.67151%
CWE
Published
1/12/2022
Updated
2/3/2023
KEV Status
No
Technology
JavaScript
Technical Details
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Package Name | Ecosystem | Vulnerable Versions | First Patched Version |
---|---|---|---|
realms-shim | npm | <= 1.2.2 |
Vulnerability Intelligence
Miggo AI
Root Cause Analysis
The PoC demonstrates prototype pollution via realm.evaluate() by manipulating stackTrace.proto.proto. The evaluate function is the primary execution mechanism for realm contexts, and its failure to properly isolate prototype chains from evaluated code enables sandbox escape. The attack modifies Error.prepareStackTrace's handling to access and pollute outer prototypes, indicating insufficient prototype isolation in the code evaluation implementation.