Critical Use-After-Free in Wasmi's Linear Memory

Summary

A use-after-free vulnerability has been discovered in the linear memory implementation of Wasmi. This issue can be triggered by a WebAssembly module under certain memory growth conditions, potentially leading to memory corruption, information disclosure, or code execution.

Impact

• Confidentiality: High – attacker-controlled memory reads possible.
• Integrity: High – memory corruption may allow arbitrary writes.
• Availability: High – interpreter crashes possible.

Affected Versions

Wasmi v0.41.0 through Wasmi v1.0.0.

Workarounds

• Upgrade to the latest patched version of Wasmi.
• Consider limiting the maximum linear memory sizes where feasible.

Credits

This vulnerability was discovered by Robert T. Morris (RTM).