Sandbox Breakout in realms-shim
Critical severity
GitHub Reviewed
Published
Oct 16, 2019
in
Agoric/realms-shim
•
Updated Jan 9, 2023
Description
Published to the GitHub Advisory Database
Oct 21, 2019
Reviewed
Jun 16, 2020
Last updated
Jan 9, 2023
Versions of
realms-shim
prior to 1.2.1 are vulnerable to a Sandbox Breakout. The Realms evaluation function has an option to apply Babel-like transformations to the source code before it reaches the evaluator. One portion of this transform pipeline exposed a primal-Realm object to the rewriting function. Confined code which used the evaluator itself could provide a malicious rewriter function that captured this object, and use it to breach the sandbox.Recommendation
Upgrade to version 1.2.1 or later.
References