Headline
CVE-2022-36025: Gas allocation error in CALL operations in Besu EVM
Besu is a Java-based Ethereum client. In versions newer than 22.1.3 and prior to 22.7.1, Besu is subject to an Incorrect Conversion between Numeric Types. An error in 32 bit signed and unsigned types in the calculation of available gas in the CALL operations (including DELEGATECALL) results in incorrect gas being passed into called contracts and incorrect gas being returned after call execution. Where the amount of gas makes a difference in the success or failure, or if the gas is a negative 64 bit value, the execution will result in a different state root than expected, resulting in a consensus failure in networks with multiple EVM implementations. In networks with a single EVM implementation this can be used to execute with significantly more gas than then transaction requested, possibly exceeding gas limitations. This issue is patched in version 22.7.1. As a workaround, reverting to version 22.1.3 or earlier will prevent incorrect execution.
Impact
An error in 32 bit signed and unsigned types in the calculation of available gas in the CALL operations (including DELEGATECALL) results in incorrect gas being passed into called contracts and incorrect gas being returned after call execution. Where the amount of gas makes a difference in the success or failure, or if the gas is a negative 64 bit value, the execution will result in a different state root than expected, resulting in a consensus failure in networks with multiple EVM implementations.
In networks with a single EVM implementation this can be used to execute with significantly more gas than then transaction requested, possibly exceeding gas limitations.
Patches
Version 22.7.1 contains a fix, ensuring that excess gas will not be allocated to inner transaction calls and correcting the excess gas errors.
Workarounds
Reverting to version 22.1.3 or earlier will prevent incorrect execution. However many ethereum mainnet networks require changes in more recent versions of Besu and should not use older versions of besu and should instead use the patched version.
Ethereum Classic and other networks not depending on a Proof of Stake transition should function fine with version 22.1.3 or earlier.
References
TBD or delete
For more information
Issue was found by Martin Holst Swende using goevmlab, it is believed that no production networks have transactions that would trigger this failure.
Related news
### Impact An error in 32 bit signed and unsigned types in the calculation of available gas in the CALL operations (including DELEGATECALL) results in incorrect gas being passed into called contracts and incorrect gas being returned after call execution. Where the amount of gas makes a difference in the success or failure, or if the gas is a negative 64 bit value, the execution will result in a different state root than expected, resulting in a consensus failure in networks with multiple EVM implementations. In networks with a single EVM implementation this can be used to execute with significantly more gas than then transaction requested, possibly exceeding gas limitations. ### Patches Version 22.7.1 contains a fix, ensuring that excess gas will not be allocated to inner transaction calls and correcting the excess gas errors. ### Workarounds Reverting to version 22.1.3 or earlier will prevent incorrect execution. However many ethereum mainnet networks require changes in more rec...