Fcron is susceptible to a local buffer-overflow vulnerability. This issue is due to the application's failure to properly bounds-check user-supplied data before copying it to an insufficiently sized memory buffer.
This issue allows local attackers to execute arbitrary machine code with superuser privileges, since the affected utility is installed setuid-superuser by default in some installations. This allows attackers to completely compromise affected computers.
Fcron version 3.0 is affected by this issue; previous versions may also be affected.
Update: This issue is now retired. Further analysis reveals that this issue cannot be exploited for code execution; therefore, this is not a vulnerability.
convert-fcrontab `perl -e 'print "pi3"x600'`