# CVE-2022-29255: Multiple evaluation of contract address in call in vyper

> Vyper compiler flaw causes double evaluation of contract addresses, leading to incorrect smart contract execution outcomes.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Jun 2022
- **Updated:** 22 Apr 2025
- **Also known as:** GHSA-4v9q-cgpw-cf38, PYSEC-2022-43053

## What is CVE-2022-29255?

CVE-2022-29255 is a high-severity vulnerability in vyperlang vyper, published on 6 Jun 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Vyper is a Pythonic Smart Contract Language for the ethereum virtual machine. In versions prior to 0.3.4 when a calling an external contract with no return value, the contract address (including side effects) could be evaluated twice. This may result in incorrect outcomes for contracts. This issue has been addressed in v0.3.4.

Weakness: CWE-670 (Always-Incorrect Control Flow Implementation)

## Which versions are affected by CVE-2022-29255?

3 open source packages ship an affected version, including vyper. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `vyper` | PyPI | All versions | 0.3.4 |
| `vyper` | PyPI | All versions | 0.3.4 |
| `vyper` | PyPI | All versions | 0.3.4 |

Products: Vyperlang Vyper.

## How do I fix CVE-2022-29255?

Upgrade vyper to 0.3.4 or later.

## Is CVE-2022-29255 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2022-29255 exists.

## Other vulnerabilities in vyperlang vyper

- [CVE-2024-24563](https://insights.sbomify.com/CVE-2024-24563/): Vyper array negative index vulnerability (critical 9.8)
- [CVE-2024-24561](https://insights.sbomify.com/CVE-2024-24561/): Vyper bounds check on built-in `slice()` function can be overflowed (critical 9.8)
- [CVE-2023-39363](https://insights.sbomify.com/CVE-2023-39363/): Vyper incorrectly allocated named re-entrancy locks (critical 9.1)
- [CVE-2022-24845](https://insights.sbomify.com/CVE-2022-24845/): Integer bounds error in Vyper (high 8.8)
- [CVE-2023-42443](https://insights.sbomify.com/CVE-2023-42443/): Vyper vulnerable to memory corruption in certain builtins utilizing `msize` (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-29255 and fix it if it is affected.

What it is: CVE-2022-29255 is a high-severity vulnerability in vyperlang vyper, published on 6 Jun 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2022-29255 exists.

Affected packages and fixed versions:
- vyper (PyPI): affected all versions; fixed in 0.3.4
- vyper (PyPI): affected all versions; fixed in 0.3.4
- vyper (PyPI): affected all versions; fixed in 0.3.4

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2022-29255/ (Markdown: https://insights.sbomify.com/CVE-2022-29255/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-29255
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-29255
- OSV: https://osv.dev/vulnerability/CVE-2022-29255

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-29255/
Summaries are generated and may contain mistakes; the official description above is the record.