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

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Create x11vnc password file with both admin and viewonly password on 12.0.4LTS

Using Ubuntu 12.0.4 LTS and need to enable x11vnc access with admin and viewonly access based on which vnc password is supplied. The x11vnc server gets started out of /etc/lightdm/start via: ...
117
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6answers
71k views

How to patch the Heartbleed bug (CVE-2014-0160) in OpenSSL?

As of today, a bug in OpenSSL has been found affecting versions 1.0.1 through 1.0.1f (inclusive) and 1.0.2-beta. Since Ubuntu 12.04, we are all vulnerable to this bug. In order to patch this ...
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2answers
334 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 ...
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1answer
24 views

Kernel security settings

What is the right security setting for the net.ipv4.conf.all.secure_redirects option in sysctl.conf? Here it sets to 1 and Here sets to 0. Is net.ipv4.conf.default.secure_redirects related to ...
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2answers
380 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 ...
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1answer
43 views

basic security tools and packages that should be installed on a public facing web server

I'm a newbie in this world and I do not have a lot of knowledge about how security works on Linux systems. I recently created a droplet on DigitalOcean with Ubuntu 13 and I've been setting it up by ...
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0answers
8 views

Juju security model issues

What plans are there to extend the security model in Juju? We see two significant issues with the current model - no internal firewalling within an environment, and the inability to expose ports to ...
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3answers
2k views

Trojan in Ubuntu? DigiNotar

On Wednesday, I installed an old copy of Ubuntu 10.04LTS onto a pristine desktop PC that I built w/ brand new hardware--DSL modem, too--except for the CPU. Then, I downloaded Ubuntu 12.04 from ...
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1answer
18 views

Can I secure a webpage with something other than username/password

I want to secure a webpage, but I want something better than username and password. Is there any public key style authentication for a webpage? I'm not concerned with the usability / convenience of a ...
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0answers
24 views

Ubuntu Repository Security [duplicate]

I notice that Ubuntu repositories is not HTTPS, all links in /etc/apt/source.list in http links. This is a peace of my repository links: deb http://archive.ubuntu.com/ubuntu saucy main restricted ...
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1answer
11 views

LOIC to work in ubuntu

i have been wondering on using LOIC(Low Orbit Ion Cannon) in ubuntu,but the problem is will it work in ubuntu 13.10 because LOIC is developed in .Net. how to get LOIC working in ubuntu?
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1answer
652 views

How to find my lost Ubuntu laptop?

I am running Ubuntu on my laptop. In case if I lose my laptop or it gets stolen, is there any way to locate it? Do I have to install any application to find my laptop?
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3answers
2k views

What do sapd, skysapd, sksapd, and ksapd do?

Does anyone know what sapd, skysapd, sksapd, ksapd do? Are they viruses? I tried clamav it didn't recognized them as viruses. I also realized that my /etc/rc.local has multiple copies of this: ...
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1answer
15 views

Remove SUID/GUID bits

SUID and SGID files on system are a potential security risk, and should be monitored closely. Is there any file in ubuntu server that recommended to remove SUID/GUID bits from it?
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0answers
34 views

Fake error report? [closed]

There was an error report window up in the top left of my screen. Usually, I get two different error reports windows. One, that's centered on the screen- which I presume is legitimate, and this other ...
5
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1answer
89 views

Rootkit on port 60001 !? Tiger says so - how do I verify? [closed]

My system is an up-to-date Ubuntu 13.10 I've installed Tiger and I'm getting this # Running chkrootkit (/usr/sbin/chkrootkit) to perform further checks... OLD: --ALERT-- [rootkit005a] Chkrootkit has ...
10
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2answers
8k 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 ...
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0answers
123 views

What does the Heartbleed bug mean for Ubuntu? Is Ubuntu not as secure as I thought? [duplicate]

I hope this question isn't closed for being subjective because I think there is a correct answer somewhere, even if it's a wiki-style explanation answer. One reason for using open source software for ...
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0answers
270 views

Mail with “3 incorrect password attempts” after starting app with sudo [closed]

A strange thing: Always after I start an application which runs with root permissions (e.g. Synaptic), I get a mail titled SECURITY information for [hostname] telling me about "3 incorrect password ...
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2answers
36 views

Security Objectives [closed]

New to Linux New to Ubuntu Objective: Better understanding security Ubuntu 12.04 LTS Hello, I am going through the security guide on Ubuntu documentation, and I am getting demotivated fast. I ...
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0answers
108 views

IptabLes and IptabLex hack? [closed]

I am running a Ubuntu 12.04.2 LTS. At a certain moment the server started to make a connection to a server with IP address 61.174.41.15 on port 9005 (tcp). We saw this happening starting on 3/4/2014 ...
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0answers
47 views

How to auto restart services when you get security updates?

That's related to the heartbleed bug. While my server (12.04 LTS) was configured to perform unattended install of all security updates, it seems that nginx was not restarted so it was still affected ...
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1answer
62 views

Ubuntu security: “antivirus” in official statement?

I use current (and vanilla) Ubuntu in a work environment. (It is, in the main, a Windows-orientated outfit.) A question has come up about antivirus, and I see this on the official Ubuntu website: ...
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0answers
25 views

SELlinux security domains

I am studying SELinux, but I can't find any clear definition for security domains. What is a security domain and what is its difference with security context?
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1answer
40 views

Are pre-releases not getting security updates? [closed]

I got a new computer a couple of weeks before the expected Trusty release date, so to save my the trouble of first installing Precise and then upgrading, I installed Trusty Final Beta. Now I see that ...
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1answer
1k views

Problem updating OpenSSL in 13.10 - How to diagnose or work around?

Following the instructions in the existing question on the OpenSSL bugs, I've run apt-get update and upgrade, and rebooted. Now when I check the version, I do not have the version mentioned in the ...
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0answers
70 views

12.04.4 server can't verify common SSL certificates, usual fixes failing

The Problem I've got one server in a farm which is suddenly unable to correctly handle SSL certificates. Attempting to do a curl command like curl -v https://google.com results in: curl -v ...
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3answers
2k views

Unable to Disable Automatic Login on 13.10

I have my settings as such, but when I power-on my laptop, it logs me right in, with no prompt. Does anyone else have this problem?
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3answers
1k views

What is pxgsettings?

Today I opened System monitor to kill an app and found three enigmatic entries labelled pxgsettings and four sh entries. See image below: Does anyone have a clue what these are? EDIT Today (2 days ...
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3answers
13k views

How to change LUKS passphrase?

Having installed Ubuntu 11.10 with whole disk encryption and LVM, I need to provide a way for users to easily change LUKS passphrase. Preferably, this should be done using GUI tools, thus, enabling ...
11
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1answer
303 views

How to deal with malware on my laptop?

I am fairly certain that my Ubuntu 13.10 laptop is infected with some sort of malware. Every once in a while, I find a process /lib/sshd (owned by root) running and consuming lots of cpu. It is not ...
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3answers
446 views

I've setup SSH Key login, but want to avoid a passphrase

I've set up a passwordless login to a friend's computer and everything works very well. I've even edited my ~/.ssh/config to add his hostname and my username. So I just type ssh friend and it ...
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40 views

Security Antivirus [duplicate]

brand new to ubuntu...I know there is way less virus problems then windows, however, is the security within the OS enough or do you suggest Antivirus program also (this is assuming the individual is ...
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1answer
49 views

Ubuntu 12.04.4 x64 - How to disable SSH daemon

I've read in this thread that running the SSH daemon with root privileges enabled by default is a potential path for malware infections: How to deal with malware on my laptop? How can I check ...
10
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3answers
4k views

How to prevent system applications (like the Software Center) from asking for password?

I'd like Software Center, Update Manager and some other system management applications to work without asking for password (like sudo does if configured with NOPASSWD) but only asking for a ...
2
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1answer
24 views

Security benefits to force users to change their password at first login

When I consider chage command, I found that I can force users to change their password at first login with following command: $ sudo chage -d 0 <user-account> Has this work any security ...
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0answers
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New user only RWX one directory

So, I read this: Is it possible to create users that can only use one directory? I would like to make it where my newly created user "kevin" (to keep in theme with the referenced post) cannot RWX in ...
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0answers
32 views

Loading/Running Customized Ubuntu Desktop 12.04 LTS i386 in RAM [closed]

I have customized my Ubuntu Desktop 12.04 LTS i386 with Ubuntu Builder and made all necessary changes and got the ISO to be reduced by 200MB. The customized version is doing good on all the PCs, ...
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2answers
30 views

Reusing old passwords

pam_cracklib module is capable of consulting a user's password "history" and not allowing them to reuse old passwords. What security risk is in reusing old passwords? If this work is useful, how many ...
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1answer
3k views

How to use sudo command in the default guest account?

How can I use sudo command from terminal in the default Ubuntu 12.04 guest account, in order to connect to vpn client and service. (OpenVPN+TrustConnect+Comodo) I know it has been disable by ...
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1answer
423 views

Somebody help me with my paranoia

I tend to be on the paranoid side, and for some time there are messages in my log file that tend to get me going close to the edge of sanity. Could someone explain the following in my auth.log file ...
3
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2answers
218 views

Which is a safe way to record Firefox passwords in Gnome Seahorse Keyring?

Searching for answers about ways to record Firefox passwords in Gnome Seahorse Keyring vault, I found severals possibilities: Firefox Gnome Keyring firefox addon from https://github.com/ in this ...
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2answers
32 views

unnecessary accounts in ubuntu

It is recommended in hardening process that remove unnecessary accounts. What security problem exist with unnecessary user account? Are there recommended user accounts that should be removed?
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0answers
15 views

full disk asymmetric encryption

Wondering if there's a protocol and open source program for full-disk, asymmetric encryption. Something like, encrypting the keys into the start of the disk (using AES/something stronger) and then ...
3
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0answers
102 views

Is having Lubuntu 12.04 a security risk?

I have a computer with Lubuntu 12.04 installed. Since unlike Ubuntu 12.04 Lubuntu is not LTS, I will not get Lubuntu updates. However, I am still getting updates (I guess these are the general Ubuntu ...
2
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1answer
191 views

How do I create one user without key authentication?

I've completed the following steps: I have configured Ubuntu server with Key authentication and it is working fine. I have disabled password authentication for key authentication to work. The server ...
2
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1answer
47 views

Prevent www-data from running scripts and programs

I discovered this little PHP script that allows you to enter GET requests manually from the browser address bar and execute commands. I played around with it and discovered that I could do all kinds ...
2
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1answer
14 views

Encrypted Lock Screens?

I really like the disk encryption to secure my funds, but my problem is I practically never have my computer off. I live a very busy life and shutting it down totally every night is entirely ...
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2answers
1k views

Building TrueCrypt on Ubuntu 13.10

With the whole NSA thing people tried to re-build identically looking binaries to the ones which truecrypt.org provides, but didn't succeed. So some think they might be compiled with back-doors which ...
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0answers
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I've lost my secuity password [duplicate]

I've lost the main password to my computer and can only boot from C.D how do I reset it to access my computer from itself?