Sudden system reboot issue

[Kauser]

Dear Concern,

Our system is running on HP-UX 11.31 system. System rebooted last two days few time and from below log, we have found below entries. 

# cat /etc/shutdownlog

12:35 Thu Feb 6, 2020. Reboot: (by sdbmblv2!oracle)
12:08 Fri Feb 7, 2020. Reboot: (by sdbmblv2!oracle)  

As per my understanding, these entries mean "oracle" user reboot the system twice. My query is can "oracle" user reboot the system as it is only a normal user not superuser priviledge?

With Best Regards,

Kauser

[Kauser]

Dear Concern,

In addition to above post, we've found no entries in /etc/shutdown.allow file.

Best Regards,

Kauser

[KishJ]

Greetings,

I am not sure what version of HP-UX is being used on this server "sdbmblv2" but you are absolutely right in saying that the user "oracle" rebooted the server twice (per shutdownlog).

An excerpt from the man page of reboot (1M)

At shutdown time a message is written in the file

/etc/shutdownlog

(if it exists), containing the time of shutdown, who ran reboot, and
the reason.

Only users with appropriate privileges can run the reboot command.

Please take note of the last time. Also, per man page of privileges (5), under "Privileges for System Calls"

reboot() PRIV_REBOOT

So, the user definitely seem to have the privileges. 

There was a potential security vulnerablity identified on HP-UX 11.11 and older versions in which local user could increase privileges. The fix was available in - PHCO_30402

I don't think there is any such vulnerability on later versions though. 

You may want to login as this user "oracle" and check it.  Also, check if this user is part of any privileged group.

[KishJ]

Hello again,

You may also want to check through the documentation :HP-UX System Administrator's Guide:Security Management HP-UX 11i Version 3" - https://support.hpe.com/hpesc/public/docDisplay?docLocale=en_US&docId=c01944073