You can make a fully open source router using free range routing (FRR) on Linux together with a switch chip mounted to a pcie card. There are also a lot of recent development around exactly this, with Vector Packet Processing, DPDK and SR-IOV to allow wire rate processing even at 100g+.
However, that Mikrotik is being mentioned as under US control stands out like a sore thumb. Given that its a Latvian company, working entirely inside the EU, having no US offices. What is much more plasable is that an attack is deploying zero-days in the routers and switches to crash or otherwise take over the equipment. That the US would be able to hide magic satellite receivers, for decades without researchers finding anything, inside of a non-US manufacturer's equipment that can get a clean signal inside of a datacenter to remotely shut them off, is so far fetched I don't even know what to say.
However, that Mikrotik is being mentioned as under US control stands out like a sore thumb. Given that its a Latvian company, working entirely inside the EU, having no US offices. What is much more plasable is that an attack is deploying zero-days in the routers and switches to crash or otherwise take over the equipment. That the US would be able to hide magic satellite receivers, for decades without researchers finding anything, inside of a non-US manufacturer's equipment that can get a clean signal inside of a datacenter to remotely shut them off, is so far fetched I don't even know what to say.