Vulnerability in Vyperlang Vyper

CVE-2024-32481

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.

EPSS: 0.008 (52.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2024-32481?
CVE-2024-32481 is a medium-severity vulnerability in Vyperlang Vyper, classified under Incorrect Conversion between Numeric Types. CVSS score: 5.3/10. Published 2024-04-25.
How severe is CVE-2024-32481?
Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2024-32481 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.