Severity: medium (5.3)

First published: Mon Sep 18 2023

Last modified: Fri Sep 22 2023

CWE: 833 667

Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine (EVM). Starting in version 0.2.9 and prior to version 0.3.10, locks of the type `@nonreentrant("")` or `@nonreentrant('')` do not produce reentrancy checks at runtime. This issue is fixed in version 0.3.10. As a workaround, ensure the lock name is a non-empty string.

### Impact Locks of the type `@nonreentrant("")` or `@nonreentrant('')` do not produce reentrancy checks at runtime. ```Vyper @nonreentrant("") # unprotected @external def bar(): pass @nonreentrant("lock") # protected @external def foo(): pass ``` ### Patches Patched in #3605 ### Workarounds The lock name should be a non-empty string. ### References _Are there any links users can visit to find out more?_

Any of

  • pip/vyper
    fixed in: 0.3.10
  • Vyperlang Vyper


  • What is CVE-2023-42441?

    CVE-2023-42441 is a vulnerability in the Vyper smart contract language that allows reentrancy attacks.

  • What is the impact of CVE-2023-42441?

    The impact of CVE-2023-42441 is that locks with the `@nonreentrant` decorator do not produce reentrancy checks at runtime, making the smart contract vulnerable to reentrancy attacks.

  • How do I fix CVE-2023-42441?

    To fix CVE-2023-42441, update to Vyper version 0.3.10 or higher.

  • Where can I find more information about CVE-2023-42441?

    You can find more information about CVE-2023-42441 at the following references: [Link 1](https://github.com/vyperlang/vyper/commit/0b740280c1e3c5528a20d47b29831948ddcc6d83), [Link 2](https://github.com/vyperlang/vyper/pull/3605), [Link 3](https://github.com/vyperlang/vyper/security/advisories/GHSA-3hg2-r75x-g69m).

  • What is the severity of CVE-2023-42441?

    CVE-2023-42441 has a severity rating of 5.3 (medium).

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