CVE-2023-32058

HIGH7.5EPSS 0.47%

Vyper vulnerable to integer overflow in loop

Published: 5/12/2023Modified: 11/19/2024

Description

### Impact Due to missing overflow check for loop variables, by assigning the iterator of a loop to a variable, it is possible to overflow the type of the latter. In the following example, calling `test` returns `354`, meaning that the variable `a` did store `354` a value out of bound for the type `uint8`. ```Vyper @external def test() -> uint16: x:uint8 = 255 a:uint8 = 0 for i in range(x, x+100): a = i return convert(a,uint16) ``` The issue seems to happen only in loops of type `for i in range(a, a + N)` as in loops of type `for i in range(start, stop)` and `for i in range(stop)`, the compiler is able to raise a `TypeMismatch` when trying to overflow the variable. thanks to @trocher for reporting ### Patches patched in 3de1415ee77a9244eb04bdb695e249d3ec9ed868 ### Workarounds

Affected packages (2)

  • PyPI/vyperfrom 0, < 0.3.8
  • PyPI/vyperfrom 0, < 3de1415ee77a9244eb04bdb695e249d3ec9ed868 | from 0, < 0.3.8

CVSS scores

SourceVersionSeverityVector
osvCVSS 4.0CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
osvCVSS 3.1HIGH7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References (5)