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

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7
votes
2answers
1k 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? ...
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?
20
votes
7answers
1k views

How should a server be secured?

Talking towards Ubuntu 10.04, server edition, what tools/practices would you recommend to secure the server?
28
votes
2answers
776 views

What precautions should I take with .debs I find on the internet?

So I was browsing the web the other day, and I came across a few places that wanted me to download .deb files - and since those are installed by root (and as such have the "powers" and capabilities of ...
26
votes
8answers
3k 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 ...
16
votes
2answers
8k views

What is the 'ptrace_scope' workaround for Wine programs and are there any risks?

To run certain Windows programs in WINE you need to this workaround: echo 0|sudo tee /proc/sys/kernel/yama/ptrace_scope According to the support websites, this is due to a bug in the Ubuntu kernel ...
14
votes
2answers
1k 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 ...
13
votes
6answers
12k views

How can I audit users and access attempts to SSH on my server?

I've had a few security problems with a server of mine, a few SSH users have been setting up fires aka giving problems. I would like to: Track user logins and logouts Track activity of these SSH, ...
31
votes
4answers
1k views

Does Ubuntu generally post timely security updates?

Concrete issue: The Oneiric nginx package is at version 1.0.5-1, released in July 2011 according to the changelog. The recent memory-disclosure vulnerability (advisory page, CVE-2012-1180, ...
13
votes
3answers
7k views

Untrusted application launcher?

Some time ago, Ubuntu introduced a Security "feature", that would only allow trusted .desktop apps to be run, on other apps it would pop up a message. Nothing new so far, However, said Message used ...
9
votes
2answers
2k views

What is the least insecure way to store a password that is used by a script?

I have a Bash script that automatically authenticates with a service using my username and password. The credentials are currently stored as plain text within the script. What precautions should I ...
3
votes
2answers
2k views

How to make a partition truly secure?

When I boot from an USB stick into my laptop I am able to mount and connect through chroot to the my hard drive and browse my files without a problem, while this has been something very very useful in ...
8
votes
2answers
343 views

How do I get security updates for restricted/partner packages?

I want to perform just security updates on Ubuntu 12.04 LTS, keeping the rest of the system unchanged. I need to do this from the command line, no the GUI update manager. I have implemented the ...
3
votes
1answer
661 views

Security and Ubuntu [closed]

I have used Linux before (Ubuntu 13.04), but I have moved back to Windows after having compatibility issues with Windows programs ex. AutoCAD and ProEngineer Wildfire. However, I tried using Linux ...
8
votes
1answer
2k views

Why should I use gksudo for Gtk apps instead of sudo? [duplicate]

I read somewhere that people should use gksudo for applications that use the Gtk GUI instead of sudo? What's the reasoning for this?
3
votes
2answers
8k views

How do I check if someone accessed my computer?

I need to check the list of files accessed in my computer (ex: yesterday on particular time). Is it possible? Or I need to check whether anybody accessed my computer (when I left it unlocked) or ...
6
votes
1answer
3k views

Does Ubuntu One effected by NSA according what Edward Snowden published? [closed]

It is very important for me to keep my files in a safe Host. I use ubuntu one because of ease of using in Ubuntu. You think is it safe enough of spying ?
2
votes
2answers
351 views

No user name/password required when exploring from live USB?

A few months back when I buggered up my netbook and then booted into it to get information from it using a live USB. (Thinking that was 10.10) When I was copy/pasting this to another USB at no time ...
51
votes
1answer
6k 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 ...
28
votes
8answers
9k views

How to set up a headless server?

I have a ubuntu development server at work. It is an old rack server that is located somewhere in the company's dungeon, where nobody ever goes. The only way it can work is as a so-called headless ...
20
votes
3answers
1k views

What automated intrusion notification/detection setup is good for home desktop use?

I've been using Linux for quite a while now and I always feel the need to have a passive software / script setup which can alert me of any suspicious network activities like scans, failed login ...
18
votes
4answers
8k views

Package denyhosts in Ubuntu Trusty Tahr is deleted: temporary or forever?

While doing a test-upgrade of our Ubuntu server to 14.04, I found that the package DenyHosts is no longer available. Installing it gives following error: apt-get install denyhosts Reading package ...
15
votes
2answers
24k views

How can I allow SSH password authentication from only certain IP addresses?

I'd like to allow SSH password authentication from only a certain subnet. I see the option to disallow it globally in /etc/ssh/sshd_config: # Change to no to disable tunnelled clear text passwords ...
44
votes
3answers
21k views

Difference between PGP and GPG

What are the main differences between PGP (Pretty Good Privacy) and GPG (GNU Privacy Guard) in relationship with security in Ubuntu and Launchpad?
13
votes
2answers
1k views

How can I tell that apparmor is working?

Some questions I want answered in the answer: How do I know if apparmor is running? How can I tell if it's working well?
10
votes
2answers
10k views

Patch OpenSSL CVE-2014-0160 on ubuntu 12.04?

NO, this is not a duplicate of How to patch the Heartbleed bug (CVE-2014-0160) in OpenSSL?. So, read on. I am seeing conflicting information with respect to Ubuntu 12.04: The Heartbleed page claims ...
5
votes
2answers
1k views

Is Chromium in Ubuntu's repository safe to use since it's so out of date?

Is Ubuntu Chromium still safe to use since its so out of date?
12
votes
1answer
205 views

How to block specific apps from opening in specific accounts

How to block certain applications from opening on certain accounts (eg: Stop account John from opening Firefox or Gimp). It is assumed this is for the GUI and not the terminal and would only apply to ...
5
votes
2answers
795 views

Precautions during SSH [duplicate]

Possible Duplicate: How can I audit users and access attempts to SSH on my server? I recently had to give away my Ubuntu 12.10 root password to one of my friends so that he could SSH into ...
2
votes
1answer
5k views

Fingerprint reader driver for Validity Sensors Fingerprint scanner

prakhar@pr3d4tOr:~$ lsusb -s 001:003 -v Bus 001 Device 003: ID 138a:0018 Validity Sensors, Inc. Fingerprint scanner Couldn't open device, some information will be missing Device Descriptor: bLength ...
12
votes
3answers
2k views

How do I call a dialog for authentication?

I am writing a gui program using wx module in python. In program whenever I am accessing a folder which requires root privilege then it asks password at terminal but I want to display the dialog to ...
10
votes
2answers
8k views

How do you set requirements (such as minimum length) on passwords?

Is there any way to set up minimum passcode requirements, such as a minimum length, requirement of mixed case alphanumerics and at least 1 symbol in the passcode, and enforce that at passcode changes? ...
9
votes
3answers
4k views

How do I safely use a virus infected USB drive in Ubuntu?

I have an USB drive which I know is virus infected (an anti-virus on my friend's machine detected it). Unfortunately neither of us know the virus name and I don't want to take the risk of plugging it ...
6
votes
4answers
4k views

Is installing wine in Ubuntu safe? [duplicate]

Possible Duplicate: Risks/Disadvantages associated with Wine According to many articles like this one, it says that windows is more vulnerable to virus. I recently installed wine on my ...
14
votes
3answers
2k views

Ubuntu vulnerable to malware sites?

I just browsed a site a while ago that was flagged as an "attack site" or has malware, but Firefox didn't warn before I went into it. Only when I opened a new tab with another page from the site did ...
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. ...
6
votes
1answer
4k views

How to either configure, or completely remove policykit? [closed]

Where can someone get policykit related tools? gnome-policykit-authorizations polkit-config-file-validate polkit-policy-file-validate And if getting them is not an option: Where can I get a full ...
3
votes
3answers
3k views

Disable usb mass storage

I want to disable usb mass storage on Ubuntu desktop 10.04, 11.04 and 11.10. As security policy to avoid data leakage. But in case of emergency there easy way getting usb mass storage back.
2
votes
0answers
7k views

Automatic unlocking of keyring? [duplicate]

Possible Duplicate: How can I stop being prompted to unlock the 'default' keyring on boot? I like the idea of gnome-keyring, but having it ask for the unlock password after every ...
19
votes
3answers
2k views

What is the “Free software only” option when installing Ubuntu?

When installing Ubuntu, you get a Free software only option. Does that Free software only option mean Free as in beer or Free as in freedom? When I say free as in freedom, I mean FSF type of ...
12
votes
1answer
776 views

Why is the automatic login disabled for users with encrypted home?

I've tried to setup an autologin, but that isn't possible, because my home is encrypted. What are the reasons for this? PS. Here I have described my problem: ...
7
votes
4answers
15k views

What rules to use for UFW?

I've decided to enable the UFW that comes with Ubuntu just to make my system even more secure (especially after watching a video of a person whose computer actually got infected!), and I've enabled ...
3
votes
1answer
232 views

Is there a security risk if a password can be reset easily?

was just reading up on changing password complexity and I stumbled upon this: https://help.ubuntu.com/11.04/ubuntu-help/user-forgottenpassword.html Isn't that a big security risk? Assuming someone ...
2
votes
6answers
6k views

How do I encrypt/decrypt file within gedit?

In the previous version of Ubuntu (eg: maverick, natty), I used to do a: sudo apt-get install gedit-plugins seahorse to have the ability to encrypt/decrypt file within Gedit after enabling the ...
1
vote
2answers
669 views

verifiying ubuntu iso with repository gpg-keys

I want to verify that a downloaded iso is not being poisend by the NSA or any other immoral agent. To do this I would very much use a signing-checking way. I am aware of VerifyIsoHowto. Still I am ...
1
vote
1answer
1k views

eth0: PACKET SNIFFER(/sbin/dhclient

Im new to Ubuntu and would like help please, I ran ProShield and got this error - eth0: PACKET SNIFFER(/sbin/dhclient I ran the following programs below and nothing came up as far as I can see. ...
0
votes
3answers
111 views

Run rkhunter regularely on a desktop system

I want to get a warning on my desktop when rkhunter finds something odd on my system. I whitelisted some files and dirs that seem ok in /etc/rkhunter.conf so I get no warnings anymore. Now I want to ...
0
votes
1answer
610 views

Can I prevent/restrict standard users from installing/uninstalling software?

Can i prevent/restrict standard user from installing/uninstalling software in Ubuntu 12.04 desktop?
20
votes
3answers
11k views

How to block internet access for wine applications?

Is it possible to prevent specific wine applications or any wine application from accessing the internet? When using certain apps under Windows, they were trying to access the internet from time to ...
49
votes
7answers
3k views

What are the risks of NOT using a firewall (home computer)?

Since a password is required to be a superuser (to install and modify programs), what are the risks to not use a firewall under Ubuntu ? More particularly if I am using a NAT router ?