Description
Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine. In version 0.3.1 and prior, bytestrings can have dirty bytes in them, resulting in the word-for-word comparisons giving incorrect results. Even without dirty nonzero bytes, two bytestrings can compare to equal if one ends with `"\x00"` because there is no comparison of the length. A patch is available and expected to be part of the 0.3.2 release. There are currently no known workarounds.
Scores
CVSS v3
7.5
EPSS
0.0024
EPSS Percentile
46.7%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-697
Status
published
Products (1)
vyperlang/vyper
< 0.3.1
Published
Apr 04, 2022
Tracked Since
Feb 18, 2026