Summary
Prior to v0.3.0, __default__() functions did not respect the @nonreentrancy decorator and the lock was not emitted. This is a known bug and was already visible in the issue tracker (vyperlang/vyper#2455), but it is being re-issued as an advisory so that tools relying on the advisory publication list can incorporate it into their searches.
A contract search was additionally performed and no vulnerable contracts were found in production.
PoC
@external
@payable
@nonreentrant("default")
def __default__():
passafter codegen:
[seq,
[if, [lt, calldatasize, 4], [goto, fallback]],
[mstore, 28, [calldataload, 0]],
[with, _func_sig, [mload, 0], seq],
[seq_unchecked,
[label, fallback],
[seq,
pass,
# Line 5
pass,
pass,
# Line 4
stop]]],
Impact
No vulnerable production contracts were found. Additionally, using a lock on a default function is a very sparsely used pattern. As such, the impact is low.
References
Summary
Prior to v0.3.0,
__default__()functions did not respect the@nonreentrancydecorator and the lock was not emitted. This is a known bug and was already visible in the issue tracker (vyperlang/vyper#2455), but it is being re-issued as an advisory so that tools relying on the advisory publication list can incorporate it into their searches.A contract search was additionally performed and no vulnerable contracts were found in production.
PoC
after codegen:
Impact
No vulnerable production contracts were found. Additionally, using a lock on a
defaultfunction is a very sparsely used pattern. As such, the impact islow.References