Libcfinder is a pwn tool made for finding the libc version that was used when compiling an executable.
Use the package manager pip to install libcfinder
pip3 install libcfinderimport libcfinder
libcv = libcfinder.find_libcv({"puts": 0xf7d8fb40, "gets": 0xf7d8f2b0})
system_addr = libcfinder.find_fun_addr(libcv[0], "puts", 0xf7dddb40, "system")