CVE-2023-42443

Technical Description

Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine (EVM). In version 0.3.9 and prior, under certain conditions, the memory used by the builtins `raw_call`, `create_from_blueprint` and `create_copy_of` can be corrupted. For `raw_call`, the argument buffer of the call can be corrupted, leading to incorrect `calldata` in the sub-context. For `create_from_blueprint` and `create_copy_of`, the buffer for the to-be-deployed bytecode can be corrupted, leading to deploying incorrect bytecode.

Each builtin has conditions that must be fulfilled for the corruption to happen. For `raw_call`, the `data` argument of the builtin must be `msg.data` and the `value` or `gas` passed to the builtin must be some complex expression that results in writing to the memory. For `create_copy_of`, the `value` or `salt` passed to the builtin must be some complex expression that results in writing to the memory. For `create_from_blueprint`, either no constructor parameters should be passed

Remediation

Check the references section for vendor advisories and patches from vyperlang. Update vyper to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References