MessagePack Ruby Gem Vulnerability: Use-After-Free in Buffer#clear
An early warning has been issued regarding a potential use-after-free vulnerability in the MessagePack::Buffer#clear method of the messagepack gem for Ruby. This vulnerability reportedly enables cross-buffer information disclosure within the same process.
What happened
The vulnerability, tracked under GHSA-4MRV-5P47-P938, is under investigation and has been reported to affect the messagepack gem for Ruby. The issue lies in the MessagePack::Buffer#clear method, which appears to have a use-after-free flaw that could lead to cross-buffer information disclosure within the same process.
Professional software engineers using the messagepack gem are advised to review their codebase for usage of MessagePack::Buffer#clear and consider upgrading to a version of the gem that includes a fix for this vulnerability, if such a version is available. The primary source for this advisory is the GitHub Security Advisory GHSA-4mrv-5p47-p938.
Further details about the affected versions, the exact nature of the vulnerability, and the availability of patches are currently under investigation. Engineers should consult the primary sources for the most up-to-date information and guidance on mitigating this potential threat.
How 0Day mitigates this
messagepack is anywhere in your dependency tree, the engineers who own the affected repositories get a push alert the moment it is flagged — no manual audit to remember to run.Read how this differs from waiting on a scanner to catch a known advisory, or see the exact, read-only access 0Day needs to do this for an organization.