However, they are easy enough to fix in C. A routine search for str...() functions followed by edits the replace them by equivalent strn...() functions each time you revisit some of your older code is very easy and should catch most problems.
I've found that searching for strcat, strcpy, sprintf and vsprintf does the job for me. The script is designed for easy extension if I find that there are library functions I need to include.
I implemented the scan in awk and drive it from a bash script called 'sanitiser'. This walks the complete source code tree while building a list of source files that need attention. I hand the list to my favourite editor by running "$EDITOR $( sanitiser )" - At the same time the script builds a file showing the lines needing attention in a hints file that can be opened in a separate window and read in parallel with editing the source.