Vulnerability · Published Dec 13, 2023 · Assigned by GitHub_M
CVE-2023-46247Vyper has incorrect storage layout for contracts containing large arrays
High 7.5
In plain English
A high-severity security flaw in vyper from vyperlang. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 53% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine (EVM). Contracts containing large arrays might underallocate the number of slots they need by 1. Prior to v0.3.8, the calculation to determine how many slots a storage variable needed used `math.ceil(type_.size_in_bytes / 32)`. The intermediate floating point step can produce a rounding error if there are enough bits set in the IEEE-754 mantissa. Roughly speaking, if `type_.size_in_bytes` is large (> 2**46), and slightly less than a power of 2, the calculation can overestimate how many slots are needed by 1. If `type_.size_in_bytes` is slightly more than a power of 2, the calculation can underestimate how many slots are needed by 1. This issue is patched in version 0.3.8.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | vyper | 0.3.8 | GHSA-6m97-7527-mh74 |
| PyPI | vyper | 0.3.8 | PYSEC-2023-307 |
Affected products (as reported)
Weakness: CWE-193, CWE-682 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
References
- https://github.com/vyperlang/vyper/security/advisories/GHSA-6m97-7527-mh74 x_refsource_CONFIRM
- https://github.com/vyperlang/vyper/commit/0bb7203b584e771b23536ba065a6efda457161bb x_refsource_MISC
- https://github.com/vyperlang/vyper/blob/6020b8bbf66b062d299d87bc7e4eddc4c9d1c157/vyper/semantics/validation/data_positions.py#L197 x_refsource_MISC