I have a few different Linksys WRT54G routers and I’ve installed DD-WRT - build number 44715 - on them. However, this build appears to have been made in 2020. So, I was wondering if there’s a more modern version of dd-wrt for this router. If not, is it possible for me to compile the latest version of OpenWRT for these routers which have 4 MB of flash and 16 MB of RAM?
Unfortunately no, not for a serious use case. Not only the RAM & storage, the CPU & networking chipset themselves are insufficient for modern security, not with reasonable performance, at least.