Vulnerability · Published Feb 2, 2024 · Assigned by GitHub_M
CVE-2024-24560Vyper external calls can overflow return data to return input buffer
Low 3.7
In plain English
A low-severity memory corruption in vyper from vyperlang. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | vyper | 0.4.0 | GHSA-gp3w-2v2m-p686 |
| PyPI | vyper | 0.4.0b1 | PYSEC-2024-148 |
Affected products (as reported)
Weakness: CWE-119 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
References
- https://github.com/vyperlang/vyper/security/advisories/GHSA-gp3w-2v2m-p686 x_refsource_CONFIRM