Описание
Multiple evaluation of contract address in call in vyper
Impact
when a calling an external contract with no return value, the contract address could be evaluated twice. this is usually only an efficiency problem, but if evaluation of the contract address has side effects, it could result in double evaluation of the side effects.
in the following example, Foo(msg.sender).bar() is the contract address for the following call (to .foo()), and could get evaluated twice
Patches
6b4d8ff185de071252feaa1c319712b2d6577f8d
Workarounds
assign contract addresses to variables. the above example would change to
References
For more information
Пакеты
vyper
< 0.3.4
0.3.4
Связанные уязвимости
Vyper is a Pythonic Smart Contract Language for the ethereum virtual machine. In versions prior to 0.3.4 when a calling an external contract with no return value, the contract address (including side effects) could be evaluated twice. This may result in incorrect outcomes for contracts. This issue has been addressed in v0.3.4.