Security :: Preventing IP Spoofing Using Ip Tables?
May 15, 2010I have a problem as following: "using iptables to prevent IP spoofing".
View 4 RepliesI have a problem as following: "using iptables to prevent IP spoofing".
View 4 Repliesis it possible to block an application from using the network? If yes, how? I read it's possible with iptables and with selinux... Also, what about creating a user who can't connect and run the application with that user?
View 7 Replies View RelatedI'd like to grant /usr/sbin/sendmail.sendmail "connectto" access to the unix_stream_socket /var/lib/imap/socket/lmtp.How do I do that?I want to eliminate error messages that keep appearing in my message log:
/var/log/messages:Jan 13 11:45:29 e setroubleshoot: SELinux is preventing /usr/sbin/sendmail.sendmail from connectto access on the unix_stream_socket /var/lib/imap/socket/lmtp. For complete SELinux messages. run sealert -l 05df828f-4402-
[code]....
When I'm logged into my account, I can't shut down the computer if someone else is also logged in unless I supply the root password. However, if I log out, I can shut down from GDM without being challenged, even though another person is logged in, which could cause problems if that person is in the middle of some work. Is there a way to password-protect the gdm shutdown function if people are logged in?
View 2 Replies View RelatedWhat methods exits to restrict which directories a user may browse on the filesystem. I want to prevent php scripts from being able to view system files. I've seen two solutions, but neither are satisfactory:Chrooting a directory that the script is in, but this requires that all the necessary php libraries/files are moved/copied into the right place relative to the chroot directory. I don't feel that I have the technical ability to achieve this.Putting php into safe mode and disabling *nasty* php functions. But this is ineffective if just one obscure *bad* php function is missed.
View 5 Replies View RelatedHow do I redirect all the UDP traffic on port 27016 of my current dedicated server to a new IP port 27015 using IP tables?
View 1 Replies View RelatedBattlefield 2 server being attacked by packets that creates infinite loop, then when a player disconnects, server crash.
The packets seems to be always the same.....
Attacker Script: [URL]
Script in action:
[Code].....
I need to find a way to block these 4 packets (i think theyre 4 for what i tested) with IP TABLES.
EDIT: There seem to be other different replies, maybe 1 different but no more.... maybe you can find something useful in the script.
I'm trying to set up an unprivileged user on some field systems running 11.04 with the standard Gnome shell (rather than Unity), and ideally that user would not have access to the command line. The user can log in through GDM (but not the text consoles) with no password, so I need to provide the absolute minimum of privileges; basically the user should only be able to run one program.
I've already set the /desktop/gnome/lockdown/disable_command_line key with gconf-editor for that user, which successfully disabled the "Run Command" dialog. Unfortunately, even though the description of the key in gconf-editor says "prevents the user from accessing the terminal...", the terminal emulator is still accessible from the Applications menu, and I haven't been able to find a good way of disabling the terminal or removing it from the menu. The only thing that occurs to me is an ugly hack: replace the gnome-terminal binary with another that checks to make sure the user is not the unprivileged one and then starts gnome-terminal.
how the file is generated or what it contains is not important at this point.The important question is how to prevent the file from being downloaded and its contents from being displayed in the browser window?Since it is not recognized by the web browser so it is downloaded on the system. That way, what the script does is exposed to the outside world.Okay, I usually keep such scripts in../cgi-bin/. But for files (text files, in the example) which are being uploaded by a user should not be downloaded by another user.
View 10 Replies View RelatedI went to print something and I get this message: Summary: SELinux is preventing access to files with the default label, default_t.
Detailed Description: SELinux permission checks on files labeled default_t are being denied. These files/directories have the default label on them. This can indicate a labeling problem, especially if the files being referred to are not top level directories. Any files/directories under standard system directories, /usr, /var. /dev, /tmp, ..., should not be labeled with the default label. The default label is for files/directories which do not have a label on a parent directory. So if you create a new directory in / you might legitimately get this label.
This is the "alert" I've received from SElinux Alert Browser after closing "rythmbox" application that opened my CreativeZen mediaplayer:
Code:
SELinux is preventing /usr/libexec/abrt-hook-ccpp from using the sys_ptrace capability
in dmesg it has:
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I keep most of my files on my server, but fiddle with them using NFS from one or another of my laptops - so they all have static IPs assigned by my router. If I want extra speed I plug in an Ethernet cable. My old DI524 wireless G router seems quite happy to have two MAC addresses (Ethernet and wireless) assigned to the same static IP, so long as I don't try using both simultaneously. However three Wireless N routers I've tried won't allow this, nor will dd-wrt.
I really don't want to have to set up every laptop as two separate hosts on my network. 'orrible complications.
Best solution I can think of is to get the Ethernet card to spoof the wireless MAC address with e.g. macchanger, as per this excellent page here: [URL] ....
I don't mind running a script manually to do that on each occasion.
This works perfectly on my old R50 Thinkpad running Debian Squeeze, but on my R60 (running Wheezy) and T400 (running Jessie), macchanger works initially, BUT as soon as I hit 'enable networking' in the Network Manager applet, the ethernet card reverts to its original setting. So of course then my router allocates a random IP and so NFS won't work.
Exactly the same goes for the iproute method 'ip link set dev eth0 address [fakemac]' - ifconfig shows it's worked, but it reverts as soon as NetworkManager goes back up.
I don't know where Network Manager (if it is that) is getting the Ethernet card's original MAC from, it seems to be listed in /etc/udev/rules.d/70-persistent-net.rules, so on the T400 (Jessie) I've even tried creating a file in /etc/udev/rules.d/75-mac-spoof.rules along the lines suggested in that archlinux page I mentioned -
ACTION=="add", SUBSYSTEM=="net", ATTR{address}=="[original MAC]", RUN+="usr/bin/ip link set dev %k address [fake MAC]"
but it seems to have no effect.
Short of reverting to Debian Squeeze on all my laptops, I don't know what else to do. Or getting into my router and reassigning the IP / MAC address by hand every time (!).
(If there's a better way to swapping easily from wireless to Ethernet when required, I'd like to know.)
Can anyone explain me the subtle difference between arp spoofing & arp poisoning ?
View 1 Replies View Relatedfor dns spoofing in my local network (one laptop and a router switched), but that does not work. An access to a specified site does not redirect.If you need any details, The command I use is:
Code:
#ettercap -T -q -i eth0 -P dns_spoof -M arp // //
How to detect a wireless LAN MAC address spoofing?
I am in an institution where we've got a wired and a wireless network, and almost every day i found a new and a strange MAC addresses in my network.
I know that because i've recorded all the MAC addresses which belongs to my network. More over, all the boxes have a fixed IP address.
So, how to detect the spoofing BOX(s) ?
There's browser identification menu for spoofing for specific sites, but i need to change user agent for all sites. How do I do it?
View 1 Replies View RelatedI've set up an email server as per this howto: [url]
In a nutshell, it uses a combinatio of postfix, dovecot, amavis (ClamAV and SpamAssisan) and mysql.
However, with this setup, authenticated users are able to spoof outgoing message by simple changing the "from" tag.
Does anyone have any ideas on how I could implement some address mapping to users?
In this setup, postfix users are NOT system users, by are stored in the database.
I have 2 routers both with 5 network cards (both different subnets). On both machines I have the following configuration: Eth0 is the internet conection, Eth1 is the conection to the other router and the other network cards are for the subnets.My current Ip tables script allows all the subnets of one router to see each other but not the subnets of the other router.
In the new situation I want not all but specific subnets to see each other (no problem here)The issue is that some of theese subnets are subnets of the other router. For example the subnet of eth2 router1 should be able to connect to eth 3 on router2. This is were eth1 comes in play. My plan was to configure iptables so that in above example eht2 would be forwarded to eth1, which will forward to eth1 on router2.Then the iptables configuration on router2 will forward it to the network card of the correct subnet.
eth2 (router1) -> eth1 (router1)
eth1 (router1) -> eth1 (router2)
eth1 (router2 -> eth3 (router2)
[code]....
I have finally gotten around to installing Ubuntu 10.4, and I really like it, but it does irk me that OpenOffice is installed by default. Is it possible to prevent OpenOffice from being installed?
View 7 Replies View RelatedI have a virtualbox installation on top of CentOS, and I need fairly high security separation between host and guest traffic. The university network the box hangs off uses statically-allocated ip addresses, allocated to fixed MAC addresses (i.e. it eats any traffic with mismatched ip and MAC addresses).
Host OS: CentOS 5.3 64bit
VBox: 3.0.4
Guest OS: Fedora 11 64bit
Hardware: dual NIC, Intel server
Bridged networking, with separate NICs for host and guest
I'm aiming for high-security separation between host and guest traffic. To do this, I would like to to run all host traffic through one NIC, H, and all guest traffic through the other, G. The host and guest have separate, statically allocated, IP addresses, IPH and IPG. The network forces these to be mapped to specific MAC addresses, MACH (the address of NIC H) and MACG (the address of NIC G).
So it's not too hard to write host firewall rules to enforce this policy. The rules just have to state that traffic coming into H must have a destination compatible with IPH, and traffic going out must have IPH as source - and vv for G and IPG. There also don't seem to be any trouble telling the guest to only use NIC G. As a result, turning off NIC G (or equivalently, firewalling it off from host traffic) crashes the network, I have to reboot it to get networking working.
But I can't figure how to tell the host (i.e. CentOS) to _only_ use NIC H for anything else except the guest. Even though we don't see any IPH traffic coming into NIC G from outside, I don't seem to be able to stop the host from starting connections on NIC G. Does anyone know any way to do this - to tell the host that it can only use IPH as its IP address unless traffic is coming from a guest process, and that it can only use address MACH and NIC H?
Recentrly my servers mysql has updated and now i have problems with my phpbb database. I cannot access some of the tables or back-up them. I did some research and founded that becouse of the update, my old my.cnf has been replaced and lost setiings for innodb. I founded the file, but i don't know how to make it work.
I do not have a back-up of the old my.cnf
I am trying to create a database and tables. Does anyone know a reference website that can help me with this or does anyone know how to do this?
View 3 Replies View RelatedI'm using ArchLinux and I have an IP tables rule that I know works (from my other server), and it's in /etc/iptables/iptables.rules, it's the only rule set in that directory. I run, /etc/rc.d/iptables save, then /etc/rc.d/iptables/restart, but when I do "iptables --list", I get ACCEPTs on INPUT,FORWARD & OUTPUT.
# Generated by iptables-save v1.4.8 on Sat Jan 8 18:42:50 2011
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
[Code]....
Where the cron tables are stored?
IE crontab -e (or -l)
and
the system one :-
sudo crontab -e (or -l)
I need to retrieve them from a system backup, don't know where to look.
We have one linux machine in the office which happens to be an important firewall. I just know the basics and need to make one changeEssentially it is forward mysql traffic to another internal machine.This is the original rule (forward to 192.20.0.17) which is working
Code:
$IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 3306 -j allowed
$IPTABLES -t nat -A PREROUTING -p TCP -i $INET_IFACE -d $STATIC_IP --dport 3306 -j DNAT -
[code]....
I want to write the shell script which
1)Finds all the databases in mysql
2)create the folder who ever is the creater of that database or owner of that database. I think the databse starts with username_ so i think i have to split the database name to get folders name . How to do that? backs up the databases belonging to that user.
Which distros are known to work with the new GPT partition tables as used with disks over 2TB?
View 5 Replies View RelatedI would like to open some port from IN to OUT pop3,smtp.whenever i tried to add some rules to existing iptables it gives me an error.Applying iptables firewall rules: iptables-restore: line 21 failed
View 7 Replies View RelatedHow to configure IP tables in opensuse?My situation is,1. My network is connected in this way...ISP -> Hub -> Firewall Router -> Switches -> DNS ->LANI need to insert a linux system with iptables configured. I am expecting it that it should be between DNS and LAN. For that I am in search of "How to configure IP tables on opensuse10.3
View 2 Replies View RelatedHow can I delete all the existing partitions on a HDD?I tried using the following command:/bin/dd if=/dev/urandom of=/dev/sda bs=1M count=10This does delete the partition tables but when I use fdisk to create new partitions, then I format those using mkfs.ntfs then the partitions are not seen by Windows.Is there any other way to remove all existing paritions from a HDD?
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