Vyper vulnerable to OOB DynArray access when array is on both LHS and RHS of an assignment
Impact
during codegen, the length word of a dynarray is written before the data, which can result in OOB array access in the case where the dynarray is on both the lhs and rhs of an assignment. here is a minimal example producing the issue:
a:DynArray[uint256,3]
@external
def test() -> DynArray[uint256,3]:
self.a = [1,2,3]
self.a = empty(DynArray[uint256,3])
self.a = [self.a[0],self.a[1],self.a[2]]
return self.a # return [1,2,3]
and here is an example demonstrating the issue can cause data corruption across call frames:
@external
def test() -> DynArray[uint256,3]:
self.a()
return self.b() # return [1,2,3]
@internal
def a():
a: uint256 = 0
b: uint256 = 1
c: uint256 = 2
d: uint256 = 3
@internal
def b() -> DynArray[uint256,3]:
a: DynArray[uint256,3] = empty(DynArray[uint256,3])
a = [a[0],a[1],a[2]]
return a
examples involving append and pop:
@internal
def foo():
c: DynArray[uint256, 1] = []
c.append(c[0])
@internal
def foo():
c: DynArray[uint256, 1] = [1]
c[0] = c.pop()
the expected behavior in all of the above cases is to revert due to oob array access.
Patches
patched in 4f8289a81206f767df1900ac48f485d90fc87edb
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?
Software afectado
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| Plataforma | Paquete | Versiones vulnerables | Corregida en |
|---|---|---|---|
| Python (PyPI) | vyper | < 0.3.8 | 0.3.8 |
Referencias
- https://github.com/vyperlang/vyper/security/advisories/GHSA-3p37-3636-q8wv
- https://github.com/vyperlang/vyper/commit/4f8289a81206f767df1900ac48f485d90fc87edb
- https://nvd.nist.gov/vuln/detail/CVE-2023-31146
- https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2023-77.yaml
- https://github.com/vyperlang/vyper
- Vector CVSS
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N- Debilidad (CWE)
CWE-787- Plataforma
- Python (PyPI)
- Paquete
vyper- Publicada
- 11.05.2023
- Actualizado
- 11.10.2026 15:17
Fuentes y licencias
OSV / GitHub Advisory Database - PYSEC-2023-77 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-3p37-3636-q8wv - CC BY 4.0
Historial de vulnerabilidades: vyper
Todas las vulnerabilidades publicadas de este paquete (Python (PyPI)), de la más reciente a la más antigua. Muestra si es un fallo aislado o un paquete que hay que vigilar.
- Entradas en total
- 47
- Primera → última
- 03.2020 10.2026
- Sin corrección
- 5
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- 0
Distribución por gravedad
- Crítica 3
- Alta 14
- Media 20
- Baja 10
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- 2020: 1
- 2021: 5
- 2022: 4
- 2023: 14
- 2024: 14
- 2025: 6
- 2026: 3
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Vyper vulnerable to OOB DynArray access when array is on both LHS and RHS of an assignment esta entrada
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