I know this is a very old thread, but as I recently ran into a similar problem, thought I'd mention that I was able to build comix (which opens cbr files) from an old (Fedora 18, which is sort of similar to RHEL7, though I believe F19 is closer).
ftp://ftp.pbone.net/mirror/archive.f...fc18.1.src.rpm.
After installing it, I ran rpm -ba comix.spec and it built without trouble. I needed a few things such as jpeg-tran but found them easily with yum provides. (If you're not familiar with that, I have a small page on it
https://srobb.net/yumprovides.html)
So, on the off chance that the OP is still looking for a way to read cbr files, that's one possible solution. Also, I think that cbr files may actually be compressed. The rpm for unrar is readily available, and if you didn't have that installed, it might be worth installing.
Again, I realize this is close to a two year old thread by now, but there's still no comix rpm for RHEL7 and this was one of the first hits I got about reading cbrs in CentOS-7, so I figure it's worth mentioning.