2026-09-12
Daily Tech Challenge
Two directories on a Linux host are both world-writable, as shown. Each contains report.txt owned by root:root with mode 0644. The unprivileged user mallory tries to delete (unlink) or rename report.txt in each directory. What happens?
$ ls -ld /tmp /var/spool/uploads drwxrwxrwt 12 root root 4096 Sep 12 09:14 /tmp drwxrwxrwx 2 root root 4096 Sep 12 09:14 /var/spool/uploads $ id uid=1001(mallory) gid=1001(mallory) groups=1001(mallory) $ ls -l /tmp/report.txt /var/spool/uploads/report.txt -rw-r--r-- 1 root root 812 Sep 12 09:10 /tmp/report.txt -rw-r--r-- 1 root root 812 Sep 12 09:10 /var/spool/uploads/report.txt
Saturday, September 12, 2026 · A new challenge drops every day