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GHSA-9p8r-4xp4-gw5w

Опубликовано: 26 фев. 2024
Источник: github
Github: Прошло ревью
CVSS3: 3.7

Описание

Vyper's _abi_decode vulnerable to Memory Overflow

Summary

If an excessively large value is specified as the starting index for an array in _abi_decode, it can cause the read position to overflow. This results in the decoding of values outside the intended array bounds, potentially leading to bugs in contracts that use arrays within _abi_decode. The advisory has been assigned low severity, because it is only observable if there is a memory write between two invocations of abi_decode on the same input.

Proof of Concept

event Pwn: pass @external def f(x: Bytes[32 * 3]): a: Bytes[32] = b"foo" y: Bytes[32 * 3] = x decoded_y1: Bytes[32] = _abi_decode(y, Bytes[32]) a = b"bar" decoded_y2: Bytes[32] = _abi_decode(y, Bytes[32]) if decoded_y1 != decoded_y2: log Pwn()

Sending the following calldata results in Pwn being emitted.

0xd45754f8 0000000000000000000000000000000000000000000000000000000000000020 0000000000000000000000000000000000000000000000000000000000000060 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffa0

Patches

Patched in https://github.com/vyperlang/vyper/pull/3925, https://github.com/vyperlang/vyper/pull/4091, https://github.com/vyperlang/vyper/pull/4144, https://github.com/vyperlang/vyper/pull/4060.

Пакеты

Наименование

vyper

pip
Затронутые версииВерсия исправления

< 0.4.0

0.4.0

EPSS

Процентиль: 67%
0.00542
Низкий

3.7 Low

CVSS3

Дефекты

CWE-119
CWE-120

Связанные уязвимости

CVSS3: 3.7
nvd
почти 2 года назад

Vyper is a pythonic Smart Contract Language for the ethereum virtual machine. If an excessively large value is specified as the starting index for an array in `_abi_decode`, it can cause the read position to overflow. This results in the decoding of values outside the intended array bounds, potentially leading to exploitations in contracts that use arrays within `_abi_decode`. This vulnerability affects 0.3.10 and earlier versions.

EPSS

Процентиль: 67%
0.00542
Низкий

3.7 Low

CVSS3

Дефекты

CWE-119
CWE-120