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🐍 PyPI

CVE-2023-32675

LOW

Nonpayable default functions are sometimes payable in vyper

Also known asGHSA-vxmm-cwh2-q762PYSEC-2023-80
Published
May 19, 2023
Updated
Apr 10, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
1 known

EPSS Exploitation Probability

via FIRST.org ↗
0.6%probability of exploitation in next 30 days
Lower Risk42th percentile+0.17%
0.00%0.35%0.70%1.05%0.2%0.6%Dec 25Apr 26Jun 26

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected
🐍vyper

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

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 default function, even if the default function is marked nonpayable. This applies to contracts compiled with vyper versions prior to 0.3.8. This issue was fixed by the removal of the global calldatasize check in commit 02339dfda. Users are advised to upgrade to version 0.3.8. Users unable to upgrade should avoid use of nonpayable default functions.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIvyperall versions0.3.8
Exploits & PoCs
1

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vyper. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update vyper to 0.3.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-32675 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether CVE-2023-32675 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2023-32675. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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 default function, even if the default function is marked `nonpayable`. This applies to contracts compiled with vyper versions prior to 0.3.8. This issue was fixed by the removal of the global `calldatasize` check in commit `02339dfda`. Users are advised to upgrade to version 0.3.8. Users unable to upgrade should avoid use of nonpayable default functions.
O3 Security · Impact-Aware SCA

Is CVE-2023-32675 in your dependencies?

O3 detects CVE-2023-32675 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.