Security :: SELinux Allow Non Root User Bind To Port <1024?
Oct 24, 2010
My understanding is SELinux adds type enforcement to standard Linux. This means that both the standard Linux and enhanced SELinux access controls must be satisfied to access an object. Which means that thing that is prevented to do in the normal standard Linux will be also prevented in the SELinux System? Does SELinux make it possible to run a non-root software to bind to a port < 1024? something that standard Linux won't allow? If not, what other suggestions do you have for allowing a program to run as non-root but able to bind to privileged ports? I know all about using the port re-direction such as ipchains, iptables.
I am encountering a wierd problem in FC12. When I try to lunch a program that listens to a lower port such as 80 or any one that is less than 1024, I always get "Permission denied" error message (I am running it as root!).Then I try starting httpd service daemon that listens to 80, no errors, the daemon started and listend to 80.PS: I checked selinux, it has been disabled.Do you have any knowledge on this case? BTW, the kernel version is:2.6.31.5-127.fc12.i686.PAE #1 SMP Sat Nov 7 21:25:57 EST 2009 i686 i686 i386 GNU/Linux
I'm simply trying to make a little restriction on www packets under two rules:
1. Allow inbound/outbound www packets (works!)
2. DROP inbound traffic to port 80 from source ports less than 1024. (DOES NOT WORK!)
Now, technically, when i use hping to test my rules, hping3 192.168.100.100 -S -p80 -s 1023 I should NOT receive any packets. However, i still receive packets, which means my rule that says less than 1024 does not work. (see below)
And this is my iptables rules in shell-script so far:
I'll explain this in one sentence: Is it possible to program a port-binding shellcode in which people across the Internet can connect to, without being thwarted by the router blocking their data because the port its bound to doesn't allow port-forwarding
I want to run a soft that is daemonized, and listens on port 6789. This soft is launched through a php page, so, by the apache user. The probl�me is that the apache user does not has rights to open / listen on a port. I tried to add apache user to the root group, but it won't help. In the application log, I have this every second :
[code]...
I tried to add apache user in the sudoers with a nopasswd but it's still a no go.
Currently working on the targeted policy, I need a help in doing the following things as quick as possible:
1- How to create a totally new SELinux user (not mapping new linux user to SELinux user) I want a new user with no roles or with a maximum of 1 role. I also need how to compile the new user so I can used it for mapping users. At the time, I've tried creating a new file inside /etc/selinux/targeted/contexts/users similar to the other users inside this directory, but it did not actually seem to appear when using the command semanage to list SELinux users : semanage user -l 2- How to create a totally new SELinux role (empty for now) ? and how to make the relation between this new role and domains or types. 3- How to create new domain, actually following some old instructions I created the .fc and .te files, but not the .if file, which is more complicated than the other 2 file.
I'm using FC8 and have installed a mailserver(postfix+dovecot),when I trying to enable the selinux mode to enforcing and i'm have some issue, the user authentication failed.if turn the selinux mode to permissive, then it work right.How can i to fix this problem?
When I confine a user myuser to the type user_u (or staff_u) with the SELinux instruction semanage login -d -s user_u myuser, this user cannot execute OpenOffice.
I suppose the problem occurs because I installed the rpm from the OpenOffice repository, not the standard OpenOffice included in FC13. However I prefer to use the rpm version, because of some bugs in the FC13 OpenOffice version. How can I create a policy to allow the execution of libicuuc and other OpenOffice libraries by my confined user ?
I configured DNS in my server while That time SELINUX enabled means It show permission denied error and some errors, but i checked all the directory permissions and all its every thing correct only but not worked..At last I just disabled the SELINUX then its working fine.I Heard SELINUX is for security for Linux operating systems, but why i disabled means only its working??
Having trouble adding a regular user with ssh access on Hardy 8.04. I can ssh into root, but not into the newly created regular user with the same ~/.ssh/authorized_keys
Code:
sshd_config has: AllowGroups sshlogin AllowUsers user root
[code]....
what could be preventing ssh login to ~user? And yes I would like to disable root ssh access, but it would be nice to be able to ssh into user first
I want full permissions for all computers in my house, without having to get up and go to the other room and change permissions for the file, folder, drive, directory, computer, etc., then go back to the other room again.
I just created a partition, as THIS user, THIS machine, rebooted, and cannot create a folder on the partition I just created. UGH. No more of this stuff... I guess at the very least, I'll still have to log onto each machine for this?
I am trying to run su as a non privileged user to log in as root. However, this only works when I make /etc/shadow world readable. I have /lib/security/unix_chkpwd as a setuid root executable
Senario is we have a system where root has authorised keys set up so that it can do a passwordless ssh to $WORKSTATION. I then need to run a script on $WORKSTATION as user "bob" and NOT as user "root". I do not want to set up user "bob" to be allowed passwordless ssh so any ideas how I can do this?I have tried variations of (as user "root"):ssh $WORKSTATION "su - bob; ./my_script"
Stumped on this one. I'm trying to set up limited sudo authority on a desktop with some sensitive user data, and as an extra precaution I wanted to configure sudo to use a password other than the user's or the root's. I'm not sure how to do this. From the manual, we have a few options, such as "runaspw" or "targetpw", but none seem quite what I'm looking for.For instance, "runaspw" could be used if I created a user for nothing other than sudo(ing) purposes, but it requires you set "runas_default", which means that said user would have to have authority to execute said commands in the first place. This is workable, but seems like a lot of extra configuration for each specific command that I want to run, as well as creating some issues with simply commands such as "shutdown" or "reboot". Also, "targetpw" can be used in conjunction with a sudo(ing)-only user if I set an alias, but, again, this isn't quite what I am looking for.
Ultimately, what I am really concerned about in this situation are keystroke loggers, so I would prefer to avoid repeated entering the user or root password when performing administrative tasks. Also, I would prefer not having to create a sudo(ing)-only user as mentioned above to prevent a comprimised password resulting in an attacker being able to log into my system.
Any Linux machine (except PCLOS) that I log into as root user seems to not start networking. I haven't tried sudo /etc/init.d/networking restart , to see if it does start, because anytime I DO this, it's for 'local' work. How about default root user configuration settings???
i want to know the risk with auto mounting flash drive as a root user,if for example there is a Usb Flash drive inserted into the system and we login into root unknowingly, and this flash drive contains an autorun script which calls a new script that can place viruses in your system, since you are in the root it will not even prompt for password and if the script is fast enough you will not even see it executing.
this is the allert i got:Code:Summary:Your system may be seriously compromised! /usr/sbin/NetworkManager tried to loada kernel module.Detailed Description:SELinux has prevented NetworkManager from loading a kernel module. All confinedprograms that need to load kernel modules should have already had policy writtenfor them. If a compromised application tries to modify the kernel this AVC willbe generated. This is a serious issue.Your system may very well be compromised.Allowing Access:Contact your security administrator and report this issue.Additional Information:
I get the problem to acess root password when i am in user login, means wahen i am in user login and want to install software from terminal then he asked root password, when i supplied root password but he give me login incorrect.
I'm using Gnome and I'd like to still have the ability to reboot/shutdown from one particular account as well as root. How would I modify the chmod command to add this ability?Also, I have a few users who just will hold the power button in to shutdown the machine. How can I keep them from doing this?// Pruned from the vintage 2007 Prevent a non-root user from shutting down, rebooting or suspend the system thread. Please create new threads instead of resurrecting ancient ones.
In our group we use NIS and have a group set up called netadmin which is given root privileges on each machine. Each machine also has a localuser called localuser created and used during installation. When logged in as a member of netadmin, attempting any action that requires root privileges (e.g. installing software in Ubuntu Software Center) results in a prompt asking for localuser's password, not the current user's password.
Does anyone know the cause? Configuration issue or Ubuntu issue? We can get around it.
When I go to single user mode for resetting root password, It ask root pawssword for login.The message displayed on prompt is "Give root password for login.On the boot prompt, I select kernel and press 'e' and after one space type 1 for single User mode and then press 'b' for booting.It shows message entering in single user mode but ask root password. Even I tried into rescue mode, but I couldn't ser root password.In rescue mode on prompt, It shows rescue login: I typed root, But when typed 'passwd' foe resetting root pawssword,It shows message unknown user and not authetication.
I am learning SELinux from LinuxCBT and I'm stuck at one place. Now video is on RHEL 4 (so tell me if things has changed since, cause I can't find anything related) shows how to disable SELinux security on httpd.first I don't know diff between initrc_t and uncofined_t; and second I don't know if something is wrong is everything is all right.
Is It possible to change a process running in root-user to non-root-user by setting suid / uid / euid / gid etc... I so please instruct how, when and wat to set in order to change a process running in root-user to non-root user
Is is possible, via iptables or something similar, to bind a service running on a specific port to a specific interface? My case: I use a VPN service for privacy. I would like to have all traffic except ftp and ssh to run over tun0. Ports 21 and 22 will need to be accessible to the outside world (eth0) while the VPN is running.
