scenario
hard
Analyze
threat-reasoning
2 points
Question 41. CSCD240-E1-C
-rwsrwxrwx root root .xhelper in /tmp. Why alarming?
Work the drill
Answer on paper or in a terminal before revealing the ideal answer.
Ideal answer
Two problems: (1) setuid-root in world-writable location = privilege-escalation footgun; (2) owned by root but with 777 (world-write) permissions means any user can replace the binary contents, gaining root the next time a priv user runs it.
Misconception bank
Each row below is a plausible wrong answer, the thinking that produces it, and the remedy that corrects the misconception. These are the foundation of the multiple-choice framing and the targeted feedback a student receives after answering.
Just a file
Misconception. Misses both setuid-root AND world-writable implications.
Remedy. Name both risks.
Authority mappings
Hover any chip for the mapping justification; click to open the authority record.
DCWF tasks:
T0250
Course-artifact links
Lectures
- CSCD240-S26-L05. Permissions part 1: ls -l anatomy, rwx, file types