1CAPTEST:(8) System Administration Utilities CAPTEST:(8)
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6 captest - a program to demonstrate capabilities
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9 captest [ --drop-all | --drop-caps | --id ] [ --lock ] [ --text ]
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12 captest is a program that demonstrates and prints out the current
13 process capabilities. Each option prints the same report. It will out‐
14 put current capabilities. then it will try to access /etc/shadow
15 directly to show if that can be done. Then it creates a child process
16 that attempts to read /etc/shadow and outputs the results of that. Then
17 it outputs the capabilities that a child process would have.
18 You can also apply file system capabilities to this program to study
20 how they work. For example, filecap /usr/bin/captest chown. Then run
21 captest as a normal user. Another interesting test is to make captest
22 suid root so that you can see what the interaction is between root's
23 credentials and capabilities. For example, chmod 4755 /usr/bin/captest.
24 When run as a normal user, the program will see if privilege escalation
25 is possible. But do not leave this app setuid root after you are don
26 testing so that an attacker cannot take advantage of it.
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30 --drop-all
31 This drops all capabilities and clears the bounding set.
32 --drop-caps
34 This drops just traditional capabilities.
35 --id This changes to uid and gid 99, drops supplemental groups, and
37 clears the bounding set.
38 --text This option outputs the effective capabilities in text rather
40 than numerically.
41 --lock This prevents the ability for child processes to regain privi‐
43 leges if the uid is 0.
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47 filecap(8), capabilities(7)
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51 Steve Grubb
52Red Hat June 2009 CAPTEST:(8)