comparatively? It's just plain ancient. Very much unsupported, lots of security vulnerabilities, etc... you shouldn't be using a version that old on the internet at all. Please upgrade to a more recent version... you may need new hardware to run any versions that are currently supported and considered safe/secure (i.e. 21.02 is the current version, 19.07 is nearing EOL, but is still supported and up-to-date on security).
You could also manually do the changes done five years ago, in year 2016, which fixed this in /etc/profile
You can just edit that file in a live router.
Ps. I thought to answer already yesterday, but when I saw that the answer/solution is from 2016, I thought that you must suffer from something else, as "nobody runs firmware older than that"...