Messages in this thread | | | Date | Tue, 21 Apr 2015 15:55:17 -0400 | From | Austin S Hemmelgarn <> | Subject | Re: [GIT PULL] kdbus for 4.1-rc1 |
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On 2015-04-21 15:38, Matthew Garrett wrote: > On Tue, Apr 21, 2015 at 11:36:54AM -0500, Eric W. Biederman wrote: >> >> HeHeHe. You mean all I need to do to get around all of the logging servers is >> capture CAP_SYS_BOOT? Say like just capture this crazy watchdog program >> that doesn't run as root so that it can only reboot the system? HeHeHe >> So I can just trigger a clean reboot wait for journald, auditd, and >> syslog all to shut down and then do evil things to the machine without >> having to worry about erasing forensic evidence? > > CAP_SYS_BOOT gives you kexec, and kexec with init=/bin/sh lets you do > anything. You added that in dc009d92435f99498cbc579ce76bf28e837e2c14 and > now the horse is long gone. Don't give CAP_SYS_BOOT to anything you > don't trust with full privileges. > The point is that Eric's suggestion works even on kernels without kexec(), which is significant because a significant number of security minded people (myself included) explicitly disable kexec in their kernel configuration.
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