Security covers a wide-ranging set of topics including Users, Permissions, Authentication, Authorisation, Upgrades, Firewalling, Hardening, etc.

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6
votes
4answers
939 views

Threats while using ubuntu?

Is there any precaution you need to take while using ubuntu? Because i dont use any antivirus available for ubuntu! So any security changes do i need to make while surfing on the net?
29
votes
8answers
6k views

What do I have to do before giving away my Ubuntu machine?

I have an old laptop that is running Ubuntu. Now I want to give away this laptop, but I want to remove all private data. So what should I remove? I don't want to format the whole system, because the ...
9
votes
3answers
19k views

How to disable cryptswap?

How can I disable cryptswap? I would like an unencrypted swap like before. This is on an ubuntu 9.10 system.
2
votes
1answer
3k views

Creating TUN device for IPSEC

Is it possible to create a separate device (like tun made by openvpn) for ipsec? If yes how can I do it?
4
votes
1answer
3k views

Where do I get the AppArmor 2.4 compatibility patch?

I just compiled the 2.6.39-rc1 kernel and AppArmor complains about a missing /sys interface (plus, it slows down the boot). Where do I get the AppArmor 2.4 compatibility patch AppArmor asks for?
1
vote
2answers
1k views

How to prevent seahorse from asking for a passphrase?

I've created one password-protected RSA key to access my remote server via ssh using key-based authentication and added it to seahorse using ssh-add. I would like to prevent seahorse from asking me ...
10
votes
3answers
5k views

Does Ubuntu use security features like DEP and ALSR?

I often read that features such as DEP (Data Execution Prevention) and ASLR (Address Space Layout Randomization) are provided on Windows. On Windows, you are given some control over turning on DEP for ...
16
votes
6answers
29k views

How to secure ubuntu server from bruteforce ssh attacks?

I have my passwords secure, but I heard people complaining about perfomance of a server going down drastically when a bruteforce attack is taking place. How can I secure my ubuntu 10.10 server from ...
0
votes
1answer
371 views

NETGEAR *Security Alert* [58:84:C7] almost on daily basis, should I do anything?

My Netgear wireless modem and router DG834PN has firewall installed and just recently I have been receiving almost daily 'security Alerts' stating; TCP Packet - Source:58.218.199.147 Destination:...
10
votes
3answers
2k views

How to secure grub recovery mode

When I boot system in to recovery mode from GRUB menu, I can get in to all powerful root without entering any password, thus insecure. How I can secure this and ensure that a password is asked every ...
1
vote
1answer
871 views

Permission problems with Clamfs

been trying to get clamfs working on Ubuntu 10.4. It seems like everything is working, clamfs locates infected files and prevents me from opening these. But I am having permission troubles with a ...
3
votes
1answer
1k views

Is full partition encryption the only sure way to make Ubuntu safe from external access?

(By "external access", I mean eg. via a Live CD, or another OS on the same dual-boot machine) A friend wants to try Ubuntu. He's fed up with Vista grinding to a crawl (the kids? :), so he likes the ...
1
vote
1answer
795 views

How can I boot from read-only filesystem while having writable partitions for logs?

I want to mount my root filesystem as read-only on boot, and use separate writable partition for logs. Is it necessary to create a ramfs image for such task? How can I do this?
2
votes
2answers
509 views

Warning about SSL ceritificate, am I under attack?

Lately I've been getting a lot of warnings about SSL certifications on my pc, Empathy keeps telling me that Facebook's certificate is self-signed and can't be trusted, and also, there are occasional ...
21
votes
2answers
6k views

How safe is Ubuntu? [closed]

Last week I started desktop sharing using krfb. Continuing from my last session, it appears that the process restarts itself. Two days ago I noticed messages popping up saying something like "...
0
votes
3answers
2k views

OpenVPN vs. IPSec - which one is faster for tunneling?

Complexity of installation of IPSec is not an issue. I would like to know which one will provide a faster connection for tunneling.
2
votes
3answers
1k views

Do any NetworkManager VPN plugins support IPv6?

Do any of the NetworkManager VPN plugins support IPv6? The two I've tried so far (PPTP and StrongSwan) only show an "IPv4" tab. I would have thought at least the IPsec one would support IPv6?
5
votes
4answers
2k views

Alternative to NetScanner

Is there a software alternative to NetScanner (which runs on the Windows platform)?
1
vote
1answer
2k views

Why is this rkhunter script sending empty emails?

I have started running rkhunter (a security monitoring tool) and I have finally managed to clear all of its warnings. Now, a cron job runs every day to monitor my machine. Rather than send me an ...
1
vote
1answer
89 views

Is it reasonable to use a GPG certificate for more than one email-account?

Are there any known issues or is this way just a time-saver for lazy people.
22
votes
2answers
2k views

How is the system kept secure?

I understand that if any malware made it's way into a Linux system, it will, at most, gain a user-level privilege and ruin anything within the particular user's reach, i.e. the user's own files. But ...
2
votes
1answer
187 views

Does Ubuntu support the OpenBSD Crypto Framework?

I can't seem to find an answer to this question. There is the Linux Crypto API, and the OpenBSD Crypto Framework (OCF). I can't find anyting on Google as to whether Ubuntu supports OCF or if the ...
6
votes
3answers
10k views

Why UFW has to be (re)started at boot time if it's only iptables rule manager?

README from source package says: When installing ufw from source, you will also need to integrate it into your boot process for the firewall to start when you restart your system. Depending on your ...
1
vote
2answers
427 views

Inetd limit access to one user

I am using telnet because of a barcode reader. It is pretty old before 2000 i think and it seems that it supports only telnet via wifi connection. However how can i restrict telnet access to only this ...
4
votes
1answer
114 views

Security in Hybrid cloud

How do we ensure security while setting up a hybrid cloud? For example, if I want to use EC2 or Rackspace, how can I make sure that the connectivity between the private and the public cloud is secure?...
10
votes
2answers
2k views

What is a security update?

Why are some updates called Important security updates? How are they different from other updates? Is my system insecure, If I don't install them? How can there be very frequent security updates? ...
1
vote
1answer
10k views

Importing PKCS#12 (.p12) files into Firefox From the Command Line

I've posted this question up on #Ubuntu and #Firefox Forums, and really could do with some help.. Anyone know where i could look or help with the answer. I'm hoping the power of social media will come ...
2
votes
1answer
838 views

Security of keyctl

Today I set up an ecryptfs directory, which is automatically mounted at login via pam. To do so i followed the guide in the ecryptfs readme ecryptfs-readme To sum up, I now have a key stored in the ...
12
votes
8answers
3k views

Is a Firewall really necessary these days? [closed]

should I install something like gufw?
13
votes
4answers
2k views

What is default password?

What is the difference between default and login? And what does Default Keyring mean? When I run some applications(Emphaty etc), Unlock Keyring window launched first, then it requires me password. ...
1
vote
1answer
710 views

Setting up fastcgi on an Ubuntu server (socket file permissions issue)

I am trying to set up mod_fcgid on my server. Part of the requirement is that Apache needs to create a socket file for mod_fcgid. I specified the folder for Apache to write the socket data to: /var/...
0
votes
1answer
955 views

Encrypted replication between normal CouchDB and Ubuntu One?

this is a very special question. Currently I'm starting to develop a new online shop using Python (Flask). I want to use CouchDB to store (and sync) new orders. But CouchDB does not encrypt the ...
22
votes
1answer
1k views

Is Ubuntu vulnerable to recent exploits using USB sticks and automount?

I read recently that someone demonstrated a security attack on a PC via the use of automount and a USB stick. How vulnerable am I to this attack and what steps are developers doing to be proactive ...
4
votes
1answer
3k views

How to prevent Synaptic Package Manager from asking for password?

This is similar to How to prevent system applications (like the Software Center) from asking for password? However that solution does not work for Synaptic Package Manager in 10.04.
13
votes
2answers
14k views

What does “pts/” in the output of w mean?

When I run w - to see who is logged on and what they are doing, i see this: USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT user tty7 :0 08:14 10:32m 44:...
0
votes
1answer
408 views

Is UbuntuOne encrypted? [duplicate]

Possible Duplicate: Ubuntu One Encryption? A simple question: is the connection between client and server encrypted and are the stored data on the server encrypted?
21
votes
2answers
26k views

chkrootkit says /sbin/init is infected, what does that mean?

I recently ran chkrootkit and got the following line: Searching for Suckit rootkit... Warning: /sbin/init INFECTED What does this mean exactly? I heard this was a false positive, ...
36
votes
17answers
36k views

Can you recommend a password generator?

I was hoping someone could recommend a good password generator. Extra props to the person who can name one that gives you a mnemonic to remember it as well.
2
votes
2answers
1k views

Making files generally available on Linux system (when security is relatively unimportant)?

I am using Ubuntu 9.10 on a stationary PC. I have a secondary 1 TB harddrive with a single big logical partition (currently formatted as ext4). It is mounted as /usr3 with options user, exec in /etc/...
8
votes
3answers
2k views

Is it possible to do a remote wipe of a system?

My office had a break-in over the weekend, and several laptops were stolen. Mine wasn't one of them, but I'm curious - the owners of the stolen computers (Windows and Mac) are all talking about remote ...
6
votes
1answer
752 views

Is troubleshooting AppArmor with 'teardown' unsafe?

I understand there is a safer, more targeted way to troubleshoot AppArmor's possible contribution to an issue than completely stopping the service and tearing down AppArmor profiles. Can someone give ...
61
votes
2answers
9k views

How to protect Ubuntu from fork bomb

I heard someone talking about a fork bomb, I did some research and found some dreadful information about some strange looking characters people can have you type at the command line and as a result do ...
18
votes
2answers
2k views

Is it a bad idea to run SELinux and AppArmor at the same time?

My corporate policy says that Linux boxes must be secured with SELinux (so that a security auditor can check the 'yes, we're extremely secure!' checkbox for each server). I had hoped to take ...
45
votes
4answers
22k views

Why is the firewall disabled by default?

Why is ufw firewall included in Ubuntu, when it is not enabled and pre-configured by default? Most users don't even know it is there, because no GUI frontend is provided.
5
votes
2answers
5k views

Copy all bridge traffic to a specific interface

I have a bridge/switch set up an a machine that has multiple ports. Occasionally, I have a vm running through virtualbox, and I'll have it use a virtual adapter and then I add the adapter to the ...
2
votes
2answers
538 views

How to make ext4 update files in place during writes

This question consists of two parts: How to find out what is the writing mode of ext4? How to configure an existing ext4 (a journaling file system) to do writes to a file in place such ...
5
votes
3answers
600 views

How to ban an IP temporarily after several incorrect password attempts?

My new server got hacked (sigh). I have physical access to my machine. It seems like the only changes made was a new user account created and a broken /etc/sudoers file. It seems as though the ...
2
votes
4answers
267 views

Security considerations for a default install?

So with an old burned install CD of Feisty Fawn I went through the process of completely formatting the Windows OS and installing Ubuntu on an old XP laptop. I then went through the online upgrade to ...
50
votes
2answers
29k views

Why shouldn't /var/www have chmod 777

When developing a page on a localhost, I sometimes get a "Permission denied" error which I can solve by running chmod -R 777 /var/www. However, people are telling me that this is a bad idea for ...
29
votes
3answers
19k views

How to block internet access for wine applications?

How can one prevent specific or any wine applications from accessing the internet? When using certain applications under Windows, they were trying to access the internet from time to time without ...