A flaw was found in Feast. The system improperly deserializes user-defined functions (UDFs) stored in its registry, which are serialized using the 'dill' library. This allows a remote attacker to store a malicious UDF, leading to unauthenticated arbitrary code execution on the feature server in default configurations. An authenticated attacker can also achieve arbitrary code execution on the registry server by bypassing authorization checks during deserialization. This vulnerability can result in cross-tenant data access and lateral movement within the system.

Feast is the open source feature store for AI and machine learning. Prior to 0.65.0, .github/workflows/printegrationtests.yml uses pullrequesttarget with the synchronize event and preserves ok-to-test, approved, or lgtm labels across newly pushed commits, allowing a fork contributor to obtain approval for a benign revision and then run changed code from refs/pull/${{ github.event.pullrequest.number }}/merge through privileged make targets. The job exposes GCP, AWS, and Snowflake credentials to that code, enabling runner code execution, credential disclosure, and possible access to downstream cloud resources. An external label-removal integration could mitigate the condition, but no repository workflow provided that protection. This issue is fixed in version 0.65.0.