Published on: Not Yet Published
Last Modified on: 09/22/2023 02:30:00 PM UTC
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 to the builtin or `raw_args` should be set to True, and the `value` or `salt` passed to the builtin must be some complex expression that results in writing to the memory. As of time of publication, no patched version exists. The issue is still being investigated, and there might be other cases where the corruption might happen. When the builtin is being called from an `internal` function `F`, the issue is not present provided that the function calling `F` wrote to memory before calling `F`. As a workaround, the complex expressions that are being passed as kwargs to the builtin should be cached in memory prior to the call to the builtin.
- CVE-2023-42443 has been assigned by security-adviso[email protected] to track the vulnerability - currently rated as HIGH severity.
- Affected Vendor/Software: vyperlang - vyper version = <= 0.3.9
CVSS3 Score: 8.1 - HIGH
|tracking issue for GHSA-c647-pxm2-c52w (memory initialization in builtins using msize) · Issue #3609 · vyperlang/vyper · GitHub|| github.com |
|memory corruption in certain builtins utilizing `msize` · Advisory · vyperlang/vyper · GitHub|| github.com |
Known Affected Configurations (CPE V2.3)