CVE-2024-32481

Description

Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. Starting in version 0.3.8 and prior to version 0.4.0b1, when looping over a `range` of the form `range(start, start + N)`, if `start` is negative, the execution will always revert. This issue is caused by an incorrect assertion inserted by the code generation of the range `stmt.parse_For_range()`. The issue arises when `start` is signed, instead of using `sle`, `le` is used and `start` is interpreted as an unsigned integer for the comparison. If it is a negative number, its 255th bit is set to `1` and is hence interpreted as a very large unsigned integer making the assertion always fail. Any contract having a `range(start, start + N)` where `start` is a signed integer with the possibility for `start` to be negative is affected. If a call goes through the loop while supplying a negative `start` the execution will revert. Version 0.4.0b1 fixes the issue.

Weakness classification

• security-advisories@github.com: CWE-681
• nvd@nist.gov: CWE-681

Primary references

• security-advisories@github.com — Product
• security-advisories@github.com — Patch
• security-advisories@github.com — Patch
• security-advisories@github.com — Exploit, Vendor Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Product
• af854a3a-2127-422b-91ae-364da2661108 — Patch
• af854a3a-2127-422b-91ae-364da2661108 — Patch
• af854a3a-2127-422b-91ae-364da2661108 — Exploit, Vendor Advisory