_abi_decode()
does not validate input when it is nested in an expression. the following example gets correctly validated (bounds checked):
x: int128 = _abi_decode(slice(msg.data, 4, 32), int128)
however, the following example is not bounds checked
@external
def abi_decode(x: uint256) -> uint256:
a: uint256 = convert(_abi_decode(slice(msg.data, 4, 32), (uint8)), uint256) + 1
return a # abi_decode(256) returns: 257
the issue can be triggered by constructing an example where the output of _abi_decode
is not internally passed to make_setter
(an internal codegen routine) or other input validating routine.
https://github.com/vyperlang/vyper/pull/3626
Is there a way for users to fix or remediate the vulnerability without upgrading?
Are there any links users can visit to find out more?
{ "nvd_published_at": "2023-09-27T15:19:32Z", "cwe_ids": [ "CWE-682" ], "severity": "MODERATE", "github_reviewed": true, "github_reviewed_at": "2023-09-26T19:34:53Z" }