Impact
A custom stateful precompile can use the is_static parameter to determine if the call is executed in a static context (via STATICCALL), and thus decide if stateful operations should be done. Previously, the passed is_static parameter was incorrect — it was only set to true if the call comes from a direct STATICCALL opcode. However, once a static call context is entered, it should stay static.
The issue only impacts custom precompiles that actually uses is_static. The maintainers estimate the usage is low. However, for those affected, it can lead to possible incorrect state transitions.
Patches
PR: https://github.com/rust-blockchain/evm/pull/133
Released in v0.36.0.
Older patch versions can be released on request if anyone needs them. Simply contact @sorpaas by email to request it.
For more information
If you have any questions or comments about this advisory:
- Open an issue in evm repo
- Email Wei at wei@that.world