These come up in CTFs all the time. One trick I don't see here is you can use `dd` to write into the `/proc` hierarchy to achieve all sorts of fuckery including patching shellcode into a running process.
You learn the most random ways to abuse program features, one I still remember because of how long it took to figure it out was an htb box that (after a long exploitation path) used NTFS ADS to hide the flag within the alternate stream in a decoy file; and of course the normal way to extract the stream was disabled so had to do some black magic with other binaries to get it
If memory serves, I got creds for a machine where the git user was able to run `git diff` with setuid, so you could abuse the pager to escape into an elevated shell.
Hey you know what, I've used dd to write into process memory but haven't actually used it to disable KASLR, so it's possible I am misremembering. My bad.
This feature is used extensively in safety-critical testing procedures, for example. It is also used as a side channel for instrumenting long-running processes.
See also: debuggers and profilers, which simply wouldn't work without this capability.
I've also since learned that this feature is used in applications (e.g. Firefox) which sandbox their processes, as a means of crash-reporting when some process pisses in their sandbox, crashing ...
Sure, it 'seems' dangerous to have this capability - until you need to debug, profile, or instrument something ..