ZKsync Era is a layer 2 rollup that uses zero-knowledge proofs to scale Ethereum. Prior to version 1.3.10, there is a very specific pattern `f(a(),b()); check_if_a_executed_last()` in Yul that exposes a bug in evaluation order of Yul function arguments. This vulnerability has been fixed in version 1.3.10. As a workaround, update and redeploy affected contracts.

era-compiler-solidity is the ZKsync compiler for Solidity. The problem occurred during instruction selection in the `DAGCombine` phase while visiting the XOR operation. The issue arises when attempting to fold the expression `!(x cc y)` into `(x !cc y)`. To perform this transformation, the second operand of XOR should be a constant representing the true value. However, it was incorrectly assumed that -1 represents the true value, when in fact, 1 is the correct representation, so this transformation for this case should be skipped. This vulnerability is fixed in 1.4.1.