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GHSA-x2c2-q32w-4w6m

Опубликовано: 30 янв. 2024
Источник: github
Github: Прошло ревью
CVSS3: 4.8

Описание

Vyper's raw_call value= kwargs not disabled for static and delegate calls

Summary

Vyper compiler allows passing a value in builtin raw_call even if the call is a delegatecall or a staticcall. But in the context of delegatecall and staticcall the handling of value is not possible due to the semantics of the respective opcodes, and vyper will silently ignore the value= argument.

A contract search was performed and no vulnerable contracts were found in production.

Details

The IR for raw_call is built in the RawCall class: https://github.com/vyperlang/vyper/blob/9136169468f317a53b4e7448389aa315f90b95ba/vyper/builtins/functions.py#L1100

However, the compiler doesn't validate that if either delegatecall or staticall are provided as kwargs, that value wasn't set. For example, the following compiles without errors:

raw_call(self, call_data2, max_outsize=255, is_delegate_call=True, value=msg.value/2)

Impact

If the semantics of the EVM are unknown to the developer, he could suspect that by specifying the value kwarg, exactly the given amount will be sent along to the target. However in fact, no value will be sent.

Here is an example of an potentially problematic implementation of multicall utilizing the raw_call built-in:

value_accumulator: uint256 = empty(uint256) results: DynArray[Result, max_value(uint8)] = [] return_data: Bytes[max_value(uint8)] = b"" success: bool = empty(bool) for batch in data: msg_value: uint256 = batch.value value_accumulator = unsafe_add(value_accumulator, msg_value) if (batch.allow_failure == False): return_data = raw_call(self, batch.call_data, max_outsize=255, value=msg_value, is_delegate_call=True) success = True results.append(Result({success: success, return_data: return_data})) else: success, return_data = \ raw_call(self, batch.call_data, max_outsize=255, value=msg_value, is_delegate_call=True, revert_on_failure=False) results.append(Result({success: success, return_data: return_data})) assert msg.value == value_accumulator, "Multicall: value mismatch" return results

Patches

Fixed in https://github.com/vyperlang/vyper/pull/3755

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

References

Are there any links users can visit to find out more?

Пакеты

Наименование

vyper

pip
Затронутые версииВерсия исправления

< 0.4.0

0.4.0

EPSS

Процентиль: 42%
0.00194
Низкий

4.8 Medium

CVSS3

Дефекты

CWE-754

Связанные уязвимости

CVSS3: 4.8
nvd
около 2 лет назад

Vyper is a pythonic Smart Contract Language for the ethereum virtual machine. Vyper compiler allows passing a value in builtin raw_call even if the call is a delegatecall or a staticcall. But in the context of delegatecall and staticcall the handling of value is not possible due to the semantics of the respective opcodes, and vyper will silently ignore the value= argument. If the semantics of the EVM are unknown to the developer, he could suspect that by specifying the `value` kwarg, exactly the given amount will be sent along to the target. This vulnerability affects 0.3.10 and earlier versions.

EPSS

Процентиль: 42%
0.00194
Низкий

4.8 Medium

CVSS3

Дефекты

CWE-754