Vyper's nonpayable default functions are sometimes payable
### Impact in contracts with at least one regular nonpayable function, due to the callvalue check being inside of the selector section, it is possible to send funds to the default function by using less than 4 bytes of calldata, even if the default function is marked `nonpayable`. this applies to contracts compiled with vyper<=0.3.7. ```vyper # @version 0.3.7 # implicitly nonpayable @external def foo() -> uint256: return 1 # implicitly nonpayable @external def __default__(): # could receive ether here pass ``` ### Patches this was fixed by the removal of the global calldatasize check in https://github.com/vyperlang/vyper/commit/02339dfda0f3caabad142060d511d10bfe93c520. ### Workarounds don't use nonpayable default functions
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2023-32675US | medium5.3 | — | ||
Vyper is a pythonic Smart Contract Language for the ethereum virtual machine. In contracts with more than one regular nonpayable function, it is possible to send funds to the defau… | ||||
references
External citations — patches, advisories, analysis.
- https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2023-80.yamlWEB
- https://github.com/vyperlang/vyperPACKAGE
- https://github.com/vyperlang/vyper/commit/02339dfda0f3caabad142060d511d10bfe93c520WEB
- https://github.com/vyperlang/vyper/commit/02339dfda0f3caabad142060d511d10bfe93c520.WEB
- https://github.com/vyperlang/vyper/commit/903727006c1e5ebef99fa9fd5d51d62bd33d72a9WEB
- https://github.com/vyperlang/vyper/security/advisories/GHSA-vxmm-cwh2-q762WEB
- https://nvd.nist.gov/vuln/detail/CVE-2023-32675ADVISORY
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