A method, system and product comprising determining a characterization of a terminal of a plurality of terminals within a binary code based on influences of the terminal, wherein the characterization of the terminal indicates a role of the terminal in the binary code; based on the characterization of the terminal, determining that the terminal is potentially affected by external input that is inputted to a device executing the binary code; determining for the terminal a corresponding propagation path within the binary code, wherein the propagation path indicates a reachability of the terminal within the binary code; locating in the binary code a code patch associated with a functionality of the binary code, wherein the code patch is associated with the propagation path of the terminal, wherein the code patch can be executed independently from the binary code; extracting the code patch from the binary code for testing; and generating an emulation of the code patch to enable fuzz testing of the emulation, whereby the code patch is tested independently.