Vyper is a Pythonic Smart Contract Language for the EVM. There is an error in the stack management when compiling the `IR` for `sha3_64`. Concretely, the `height` variable is miscalculated. The vulnerability can't be triggered without writing the `IR` by hand (that is, it cannot be triggered from regular vyper code). `sha3_64` is used for retrieval in mappings. No flow that would cache the `key` was found so the issue shouldn't be possible to trigger when compiling the compiler-generated `IR`. This issue isn't triggered during normal compilation of vyper code so the impact is low. At the time of publication there is no patch available.

Affected: PyPI: vyper

### Summary There is an error in the stack management when compiling the `IR` for `sha3_64`. Concretely, the `height` variable is miscalculated. The vulnerability can't be triggered without writing the `IR` by hand. That is, it cannot be triggered from regular vyper code, it can only be triggered by using the `fang` binary directly (this binary used to be called `vyper-ir` prior to v0.3.4).

### Details To compile `sha3_64`, the `arg[0]` and `arg[1]` have to be compiled: https://github.com/vyperlang/vyper/blob/c150fc49ee9375a930d177044559b83cb95f7963/vyper/ir/compile_ir.py#L585-L586

As can be seen, after compiling the 0th arg, the `height` variable isn't increased. If new `withargs` are defined in the inner scope, they are manipulated correctly, because both their `height` is off and also the global `height` is off and thus their placement on the stack is computed correctly.

`sha3_64` is used for retrieval in mappings. No flow that would cache the `key` was found, the issue shouldn't be possible to trigger when compiling the compiler-generated `IR`.

### PoC Suppose the following hand-written IR: ```lisp (with _loc (with val 1 (with key 2 (sha3_64 val key))) (seq (sstore _loc (with x (sload _loc) (with ans (add x 1) (seq (assert (ge ans x)) ans)))))) ``` after compilation: ``` the generated bytecode: 6001600281806020525f5260405f2090509050805460018101818110610026579050815550005b5f80fd

0000 60 PUSH1 0x01 0002 60 PUSH1 0x02 0004 81…

Affected: PyPI: vyper

Vyper is a Pythonic Smart Contract Language for the EVM. There is an error in the stack management when compiling the `IR` for `sha3_64`. Concretely, the `height` variable is miscalculated. The vulnerability can't be triggered without writing the `IR` by hand (that is, it cannot be triggered from regular vyper code). `sha3_64` is used for retrieval in mappings. No flow that would cache the `key` was found so the issue shouldn't be possible to trigger when compiling the compiler-generated `IR`. This issue isn't triggered during normal compilation of vyper code so the impact is low. At the time of publication there is no patch available.