Security Mechanisms of UNIX Flashcards
What are the principals in UNIX?
user identifies (UID) and group identifiers (GID)
what is a user identifier?
each user has a unique number (16 or 32 bit)
what is a group identifier?
each group has a unique number (16 or 32 bit)
what is UID 1 - 999?
reserved for specific operating tasks
UID >= 1000
assigned to human users
what is the username and UID of the superuser?
root, 0
what is a process?
an instance of code in execution
what is a PID?
process identifier
what does the ssh process do?
offers remote login service with username/password authentication
What does the ping program do?
provides users with network ping facility
what are 4 standard attack methods with Set-User-ID programs?
- memory corruption
- command injection during sub-process invocation
- providing an unexpected execution environment
- race conditions
what are 3 precautions you can take to prevent Set-User-ID program attacks?
- programs should have set-user-if status if absolutely necessary
- programs should drop their privileges asap
- inputs to set-user-ID need to be checked with extreme care
what are objects (mainly)?
files and processes
what is the central UNIX paradigm?
“Everything is a file”
what is an inode?
a data structure on a traditional unix-style file systems
