CVE-2024-24560
Vyper's external calls can overflow return data to return input buffer
Description
Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine. When calls to external contracts are made, we write the input buffer starting at byte 28, and allocate the return buffer to start at byte 0 (overlapping with the input buffer). When checking RETURNDATASIZE for dynamic types, the size is compared only to the minimum allowed size for that type, and not to the returned value's length. As a result, malformed return data can cause the contract to mistake data from the input buffer for returndata. When the called contract returns invalid ABIv2 encoded data, the calling contract can read different invalid data (from the dirty buffer) than the called contract returned.
How to fix CVE-2024-24560
To remediate CVE-2024-24560, upgrade the affected package to a fixed version below.
- —upgrade to 0.4.0 or later
- —upgrade to 0.4.0b1 or later
Is CVE-2024-24560 being exploited?
Low — EPSS is 0.9%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 0.4.0
- from 0, < 0.4.0b1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | LOW3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N |