Softpanorama (slightly skeptical) Open Source Software Educational Society

May the source be with you, but remember the KISS principle ;-)

Solaris 9 RC Scripts

Any installation of Solaris loads many packages that are not needed for a server to function. However, even if you remove unneeded packages, there are several startup services which can be disabled. As part of your minimalization process, you want to reduce number of processes and services running on your server. Some of these unneeded services can pose a potential security risk. There are two main places to configure which services are active: the /etc/inetd.conf file and the /etc/rc.X/ directories.

inetd.conf

This file specifies which ports the inetd daemon will listen for. You eliminate uneccessary services by commenting them out. There are many web tutorials on configuring the inetd.conf file.

rcX.d services

/etc/rcX.d contains startup and shutdown scripts. (The startup scripts start with "S", the shutdown with "K". The standard recommendation is to rename the uppercase S to a lowercase one. However, Jeff Campione recommends renaming files with a prefix of "NO". My friend Jeff Veiss moves files into a subdirectory called "disabled".

The following table displays each of the Solaris Startup files, where they are placed, and which distribution and package they are part of. (I left out the "K" files for brevity. A list of resources which recommend which scripts can be disabled follows):

• The above table assumes that you've performed a standard SUNCWreq, SUNWCuser, SUNWCprog or SUNWCall install.
• Therefore, any scripts belonging to the SUNWCXall metacluster installed on your system (such as S75flashprom) may be necessary for your system's functioning and should not be deleted without careful consideration.
• Therefore,carefull examine your system before following checklists or scripts which "delete all files except the following"...
• The packages listed are representative; some of the startup files may be created from more than one package. (Perhaps I should have listed the cluster the package belongs to...)
• The vast majority of startup files belong in the SUNWcsr (Core Solaris) package which is installed as part of every Solaris installation. Others may not be created depending on which OS group and packages installed on the system.
• Third party software may install additional startup files.
• Files in /etc/init.d are links to these files and usually are named the same but without the "Sxx" prefix.

Many of these scripts need to be disabled, some need to be modified, and a few need to be created.

Which ones can be disabled?
Unless you are absolutely sure, don't delete a startup file, just disable it. There is a difference between deleting a file and preventing them from starting up...

If sure are sure you don't need a file, then change its name or move it to a subdirectory called "disabled":

mkdir /etc/rc1.d/disabled/ mkdir /etc/rc2.d/disabled/ mkdir /etc/rc3.d/disabled/ mv -f /etc/rc2.d/S*asppp /etc/rc2.d/disabled/

Which ones need to be modified?
Some of the existing rc files should be modified to add additional logging or increase security. For example, The line in /etc/rc2.d/S72inetsvc: /usr/sbin/inetd -s should be modified to read /usr/sbin/inetd -s -t in order for inetd to trace the incoming connections. Syslog will now log the client's ip address and port number, along with the name of the service. You probably also should comment out the multicast route (224.0.0.0) located within this file.

Additional Startup Files
The experts recommend creating /etc/rc3.d/S70nddconfig (and a link to /etc/init.d/nddconfig). This file will contain ndd commands designed to increase network security. (Solaris Operating Environment: Network Settings for Security). Jeff Campione also recommends creating an /etc/rc2.d/S75sshd startup script. If you have any static routes or proxy arp entries, create a file /etc/rc2.d/S99static_routes and place the arp and "route" commands in it. (Source: YASSP-Post installation steps))

Titan also creates a /etc/rc3.d/S79tmpfix (/etc/init.d/tmpfix) to change the "sticky bit" on the /tmp directory.

Recommended Links

http://www.securityfocus.com/focus/sun/articles/install.html- Securityfocus

http://www.roble.com/docs/secure_solaris.html- Roble

http://www.ist.uwaterloo.ca/security/howto/2000-09-19.html - Univ of Waterloo (good discussion of services, also a script to shut them off)

http://www.usenix.org/sage/sysadmins/solaris/solaris/services.html#startups- Sage

http://www.sabernet.net/papers/Solaris.html- Sabernet

http://www.fish.com/titan- Titan

http://www.sans.org/y2k/practical/Jeff_Campione_GCUX.htm- Jeff Campione/Sans

http://www.sun.com/blueprints/1200/network-updt1.pdf,
http://www.sun.com/solutions/blueprints/1299/network.pdf - Solaris Operating Environment: Network Settings for Security

http://www.yassp.org/after.html- YASSP: Post installation steps

Last modified: June 05, 2008