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HIGH7.3

GHSA-75jp-vq8x-h4cq

Wasmi Out-of-bounds Write for host to Wasm calls with more than 128 Parameters

Details

### Summary

In the WASMI Interpreter, an [Out-of-bounds Buffer Write](https://cwe.mitre.org/data/definitions/787.html) will arise arise if the host calls or resumes a Wasm function with more parameters than the default limit (128), as it will surpass the stack value. This doesn’t affect calls from Wasm to Wasm, only from host to Wasm.

### Impact

After conducting an analysis of the dependent Polkadot systems of `wasmi`: [Pallet Contracts](https://github.com/paritytech/polkadot-sdk/tree/master/substrate/frame/contracts), [Parity Signer](https://github.com/paritytech/parity-signer), and [Smoldot](https://github.com/smol-dot/smoldot), we have found that none on those systems have been affected by the issue as they are calling host to Wasm function with a small limited amount of parameters always.

### Mitigations

If you are using `wasmi` betwen version 0.15.0 and 0.31.0, please update it to the [0.31.1](https://github.com/paritytech/wasmi/releases/tag/v0.31.1) patch release that we just published.

### Workarounds

Ensure no more than 128 parameters can be pass in a call from the host to a Wasm function.

### References

Patch PR: <PR>

### Special thanks

Special thanks to Stellar Development Foundation for reporting this security vulnerability.

Are you affected?

Enter the version of the package you're using.

Affected packages

crates.io/wasmi
Introduced in: 0.15.0Fixed in: 0.31.1

Upgrade wasmi to 0.31.1 or newer (ecosystem crates.io).

References