vyper vulnerable to storage allocator overflow
Impact
The storage allocator does not guard against allocation overflows. This can result in vulnerabilities like the following:
owner: public(address)
take_up_some_space: public(uint256[10])
buffer: public(uint256[max_value(uint256)])
@external
def initialize():
self.owner = msg.sender
@external
def foo(idx: uint256, data: uint256):
self.buffer[idx] = data
Per @toonvanhove, "An attacker can overwrite the owner variable by calling this contract with calldata: 0x04bc52f8 fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff5 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff (spaces inserted for readability)
0x04bc52f8 is the selector for foo(uint256, uint256), and the last argument fff...fff is the new value for the owner variable."
Patches
patched in 0bb7203b584e771b23536ba065a6efda457161bb
Workarounds
Is there a way for users to fix or remediate the vulnerability without upgrading?
References
Are there any links users can visit to find out more?
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | vyper | < 0.3.8 | 0.3.8 |
References
- https://github.com/vyperlang/vyper/commit/0bb7203b584e771b23536ba065a6efda457161bb
- https://github.com/vyperlang/vyper/security/advisories/GHSA-mgv8-gggw-mrg6
- https://nvd.nist.gov/vuln/detail/CVE-2023-30837
- https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2023-76.yaml
- https://github.com/vyperlang/vyper
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N- Weakness (CWE)
CWE-789- Platform
- Python (PyPI)
- Package
vyper- Disclosed
- 05.05.2023
- Updated
- 11.10.2026 15:17
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2023-76 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-mgv8-gggw-mrg6 - CC BY 4.0
Vulnerability history: vyper
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 47
- First → latest
- 03.2020 10.2026
- Without a fix
- 5
- Exploited in attacks
- 0
Severity breakdown
- Critical 3
- High 14
- Medium 20
- Low 10
Disclosures per year
- 2020: 1
- 2021: 5
- 2022: 4
- 2023: 14
- 2024: 14
- 2025: 6
- 2026: 3
-
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