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.

Affected: PyPI: vyper

### Impact bytestrings can have dirty bytes in them, resulting in the word-for-word comparison to give incorrect results, e.g. ```vyper b1: Bytes[32] = b"abcdef" b1 = slice(b1, 0, 1) b2: Bytes[32] = b"abcdef" t: bool = b1 == b2 # incorrectly evaluates to True ``` even without dirty nonzero bytes, because there is no comparison of the length, two bytestrings can compare to equal if one ends with `"\x00"`. ```vyper b1: Bytes[32] = b"abc\0" b2: Bytes[32] = b"abc" t: bool = b1 == b2 # incorrectly evaluates to True ```

### Patches fixed in https://github.com/vyperlang/vyper/commit/2c73f8352635c0a433423a5b94740de1a118e508

Affected: PyPI: vyper

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.