CVE-2024-32646

Advisory

In Vyper versions 0.3.10 and prior, using the `slice` builtin can result in a double eval vulnerability when the buffer argument is either `msg.data`, `self.code` or `<address>.code` and either the `start` or `length` arguments have side-effects. It is much harder (but not impossible!) to trigger the bug since 0.3.4 since the unique symbol fence was introduced. No vulnerable production contracts were found. Additionally, double evaluation of side-effects should be easily discoverable in client tests. As such, the impact is low.

Affected package

Affected versions

Fixed versions

Vulnerability changelog

Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. In versions 0.3.10 and prior, using the `slice` builtin can result in a double eval vulnerability when the buffer argument is either `msg.data`, `self.code` or `<address>.code` and either the `start` or `length` arguments have side-effects. It can be easily triggered only with the versions `<0.3.4` as `0.3.4` introduced the unique symbol fence. No vulnerable production contracts were found. Additionally, double evaluation of side-effects should be easily discoverable in client tests. As such, the impact is low. As of time of publication, no fixed versions are available. See CVE-2024-32646.


MISC:https://github.com/vyperlang/vyper/security/advisories/GHSA-r56x-j438-vw5m: https://github.com/vyperlang/vyper/security/advisories/GHSA-r56x-j438-vw5m

Resources

• https://github.com/vyperlang/vyper/security/advisories/GHSA-r56x-j438-vw5m
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-32646