Vulnerability · Published Jan 18, 2024 · Assigned by GitHub_M
CVE-2024-22419concat built-in can corrupt memory in vyper
High 7.3
In plain English
A high-severity buffer overflow in vyper from vyperlang. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 56% 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. The `concat` built-in can write over the bounds of the memory buffer that was allocated for it and thus overwrite existing valid data. The root cause is that the `build_IR` for `concat` doesn't properly adhere to the API of copy functions (for `>=0.3.2` the `copy_bytes` function). A contract search was performed and no vulnerable contracts were found in production. The buffer overflow can result in the change of semantics of the contract. The overflow is length-dependent and thus it might go unnoticed during contract testing. However, certainly not all usages of concat will result in overwritten valid data as we require it to be in an internal function and close to the return statement where other memory allocations don't occur. This issue has been addressed in 0.4.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | vyper | 0.4.0 | GHSA-2q8v-3gqq-4f8p |
| PyPI | vyper | 0.4.0b1 | PYSEC-2024-103 |
Affected products (as reported)
Weakness: CWE-120 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
References
- https://github.com/vyperlang/vyper/security/advisories/GHSA-2q8v-3gqq-4f8p x_refsource_CONFIRM
- https://github.com/vyperlang/vyper/issues/3737 x_refsource_MISC
- https://github.com/vyperlang/vyper/commit/55e18f6d128b2da8986adbbcccf1cd59a4b9ad6f x_refsource_MISC