CVE-2024-32648
vyper default functions don't respect nonreentrancy keys
Impact
### Summary Prior to v0.3.0, `__default__()` functions did not respect the `@nonreentrancy` decorator and the lock was not emitted. This is a known bug and was already visible in the issue tracker (https://github.com/vyperlang/vyper/issues/2455), but it is being re-issued as an advisory so that tools relying on the advisory publication list can incorporate it into their searches. A contract search was additionally performed and no vulnerable contracts were found in production. ### PoC ```vyper @external @payable @nonreentrant("default") def __default__(): pass ``` after codegen: ``` [seq, [if, [lt, calldatasize, 4], [goto, fallback]], [mstore, 28, [calldataload, 0]], [with, _func_sig, [mload, 0], seq], [seq_unchecked, [label, fallback], [seq, pass, # Line 5 pass, pass, # Line 4 stop]]], ``` ### Impact No vulnerable production contracts were found. Additionally, using a lock on a `default` function is a very sparsely used pattern. As such, the impact is `low`.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | vyper | <= 0.2.16 | 0.3.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Vyperlang | Vyper | before 0.3.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/vyperlang/vyper/commit/93287e5ac184b53b395c907d40701f721daf8177
- https://github.com/vyperlang/vyper/issues/2455
- https://github.com/vyperlang/vyper/security/advisories/GHSA-m2v9-w374-5hj9
- https://github.com/advisories/GHSA-m2v9-w374-5hj9
- https://nvd.nist.gov/vuln/detail/CVE-2024-32648
- https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2024-163.yaml