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

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5
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2answers
2k views

How to truly secure a hard-drive?

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 ...
45
votes
5answers
60k views

How to encrypt individual folders?

Let's say that I have a folder, within my Documents folder, that has files I want no one to access without a password. Is there a way to lock down that folder so that it's password protected / ...
4
votes
2answers
2k views

Can ecryptfs-setup-private be made to use a 256 bit AES key (instead of the default 128 bit key length)?

ecryptfs-setup-private will by default use an AES 128 bit key. Can I make it use a 256 bit key (32 bytes key length)? Of course, I could do the whole process manually as described here: ...
18
votes
3answers
27k 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 ...
2
votes
1answer
28 views

Is there a way to tell which application last accessed your camera?

Is there an application which will tell me which programs have last accessed my camera?
0
votes
1answer
44 views

How to password-protect an individual folder

I have to password-protect two folders: folder A is on my computer's hard drive, and folder B is on an external hard drive. Regarding folder A: I have tried encrypting folder A using Cryptkeeper but, ...
4
votes
1answer
9k 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 ...
0
votes
0answers
39 views

Where do I have to specify Security Policies for Ubuntu Touch applications?

Here https://wiki.ubuntu.com/SecurityTeam/Specifications/ApplicationConfinement/Manifest I read that I have to fill the manifest.json file included in the package, but I also read that MyApps provides ...
0
votes
0answers
11 views

Why is Ubuntu only using SHA1 for WDE?

I'm wondering. In times where Hardware gets faster every week and all the NSA thingies about Snowden and such, why is Ubuntu still using Sha1 when encrypting the system over the GUI (the installer) I ...
0
votes
2answers
72 views

Is it safe to download and open files? [closed]

I understand that a virus and malware can exists in Linux. However, I have read a lot about how Linux is not vulnerable to viruses because of a variety of reasons. So does that mean that I can ...
5
votes
1answer
73 views

Is universe checked by the Ubuntu Security team?

I have a generall question regarding the Ubuntu universe repository. Does anybody know if they are checked by Ubuntu Security Team? Will they move or delete packages if any problem is encountered ...
0
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0answers
49 views

Asus K52Jr webcam notification LED always lit

I have been using Ubuntu 14.10 on my Asus K52Jr notebook for some time now, and this always bothered me. The webcam's LED is always lit (on Windows it only lights up if it's in use), and I'm concerned ...
0
votes
0answers
66 views

java security prompt even with exception list

I'm trying to run an applet of a website, and a prompt pops up with "Application blocked by security Java" but I have this website on the exception list! I'm running ubuntu 14.04 and Java Version 8 ...
4
votes
3answers
627 views

Where can I find the SHA256 hashes of Ubuntu images?

I'm trying to securely validate the hash of a downloaded ubuntu-11.04-alternate-amd64.iso but it seems I just can't find any. I found this site: https://help.ubuntu.com/community/UbuntuHashes but ...
0
votes
1answer
488 views

How to add user from apache user group in linux

The question is simple. How we can add user without root privileges (because www-data is very important for security)? For example adding user with root user: sudo adduser user group Without root ...
3
votes
3answers
3k views

Packet Sniffer found, what next?

After a download yesterday my computer crashed. I updated today and checked for rootkits. I found a packet sniffer eth0: PACKET SNIFFER(/sbin/dhclient[3966]) How can I remove this?
1
vote
1answer
58 views

ip forwarding enabled at every boot

Recently I noticed that cat /proc/sys/net/ipv4/ip_forward returns 1, something that is not recommended and I generally do not enable things I do not need that increase my attack vector. I thought, ...
1
vote
2answers
68 views

Can Port Forwarding to a Windows VM cause Security problems? [closed]

I have question. My physical host is Ubuntu 14.04. I installed Virtualbox with a Windows Server 2012 VM with IIS. I set port forwarding from my Ubuntu host to my vm. If my virtual Windows Server ...
2
votes
0answers
126 views

How do we implement requirements of password policy?

This question might look similar but I could not find a solution to this which covers all the below requirements of the policy, Hence please help me: - Incorrect pass lockout (after 3 incorrect ...
23
votes
2answers
31k 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 ...
0
votes
0answers
113 views

Migration from Truecrypt to LUKS

I am looking for an alternative for True-crypt which can be used both at the disk level and with portable media. Having installed Ubuntu 14.04 ticking 'with disc encryption' enabled, it works very ...
0
votes
1answer
131 views

Will Editing HOSTS file in Ubuntu Improve my Network Security?

I have recently learnt about 2 different ways of editing the hosts file in Ubuntu for the purpose of blocking webpages and domains tracking my computer (protecting myself from tracking cookies), and I ...
7
votes
2answers
248 views

/var/log suspicious entries

For fun I tailed /var/log/auth.log (tail auth.log) and there were many of the following: sshd[16225]: Received disconnect from 203.100.83.32: 11: Bye Bye [preauth] The ip appears to be from ...
1
vote
1answer
62 views

New to Ubuntu-updates, security, on Acer Aspire One ZG5

All, I'm completely new to Ubuntu but am looking forward to working with it. I have an Acer Aspire One ZG5 (150?) from about 2008. From what I can gather, I should install 12.10 (this appears to be ...
2
votes
1answer
252 views

What are the possible threats if internal IP address is publicly revealed?

In many cases, people do not take enough care to remove their IP addresses from some output before posting it to help forums and Q&A sites like askubuntu. Considering one's IP address is revealed ...
0
votes
1answer
42 views

How to perform detail packet capture on Ubuntu firewall?

I've routed internet traffic of my other systems on this ubuntu linux system where I have configured packet forwarding. but still I am unable to get internet on other systems. Hence I want to ...
2
votes
1answer
41 views

Will creating a directory inside a system directory with 777 permission cause security vulnerability?

Can creating directories with 777 permission inside system directories cause any security weakness? For example, say I open a directory called Custom inside /usr/share/backgrounds/ and give it 777 ...
0
votes
1answer
101 views

Ubuntu 14.04 and 14.10 Can't login to some secure website logins

I can generally google to find solutions to problems I have with Ubuntu, but this one has me stumped. I have been using Ubuntu 14.04 for several months, on this computer. I use Chrome as my primary ...
16
votes
5answers
14k views

How to detect and remove a Linux trojan?

I recently (re)stumbled upon this: Linux Trojan Goes Unnoticed For Almost A Year (Unreal IRCd) Yes, I know that adding some random PPA/software from an untrusted source is asking for trouble (or ...
2
votes
3answers
462 views

How can I tell if a CVE has been fixed in Ubuntu's repositories?

Today a couple of buffer overflows in NTP were announced 1, 2. It looks like updating my system to fix these issues is in order. How can I find out if they have been fixed in the Ubuntu ...
1
vote
1answer
53 views

Looking for network surveillance tool

I sometimes use / test software that cannot be found in the apt tree. The software comes from all over the internet. When executing the software I create an extra user for this particular software and ...
5
votes
2answers
3k 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 ...
3
votes
2answers
236 views

Where to store a Keepass password file?

Where would you recommend me to store a Keepass file? Usually I have my personal documents in my Dropbox account. Would it be safe to use Dropbox for this file?
0
votes
1answer
54 views

How do I unlock system tools such as users and date and time

I'm using Ubuntu Server 14.04 with Gnome and suddenly I can't unlock system settings such as Users and time & date: the unlock icon is grayed out even though I'm an administrator and terminal ...
12
votes
1answer
259 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 ...
0
votes
1answer
501 views

How can you test for a DNS leak for an OpenVPN provider?

I'm currently using VPNBook with OpenVPN. I just recently learned about DNS leaking. Is there a way to scan for it?
0
votes
1answer
248 views

Package with bad signature got instlaled on second try: how?

I executed my daily sudo apt-get update && sudo apt-get upgrade command, and got a bad signature error when hitting google chrome: Fetched 2178 kB in 2s (981 kB/s) Reading package lists... ...
29
votes
5answers
5k views

What's wrong with using sudo?

In a comment here I've been told that unnecessarily using sudo should be avoided. While it wasn't needed in that particular case, I don't see any harm in using it. I think that when executing trivial ...
0
votes
1answer
34 views

Do I stick with 12.04 lts or upgrade to 12.10 or higher?

I recently bought a laptop with ubuntu 12.04 LTS. I have only used windows so far, so I admit I'm a noob at ubuntu. Since I only need it for reading, writing papers, entertainment and communication, ...
24
votes
6answers
19k views

What Can Be Done To Secure Ubuntu Server?

I have a project to secure Ubuntu Server as much as I can. The server is a web hosting server. The server will be running LAMP , Mail , and DNS.
1
vote
2answers
53 views

A Software Center review claims Ruby has a virus. Is it accurate?

I'm working on a Javascript webapp and trying to figure out how to add documentation. It seems like the only option is to install something that lives on a server. I thought maybe I'd try JSDuck. It ...
0
votes
0answers
29 views

ima-evm in 14.04 server?

I was looking for an Ubuntu-packaged ima-evm-utils for Trusty server (amd64), but no luck. (It is available in 14.10.) While I can build this from source, it would be better to have a supported ...
36
votes
4answers
14k 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.
1
vote
1answer
282 views

How to force SMB2 protocol in samba?

For security reasons, I'd like to disable the SMB1 protocol in samba. Is it possible? I'm running Ubuntu 14.04 LTS.
1
vote
0answers
127 views

Allow one process access to /dev/uninput without completely compromising security

Steam In-Home-Streaming was turned back on the other day. This allows you to play games being rendered on one computer on another computer (commonly playing games on a TV/Media Centre that are being ...
0
votes
1answer
80 views

Wrong timestamp in syslog

I was taking a look on my syslog, and I found this: Nov 30 22:30:01 nori-hidamari NetworkManager[963]: <info> (wlan0): canceled DHCP transaction, DHCP client pid 2580 Nov 30 22:30:01 ...
0
votes
2answers
44 views

Can anybody read my password protected hard drive files using my hard drive as secondary hard drive?

So i have a laptop with ubuntu as OS. now can anyone having physical access to my hardrive ,see my data just by simply using it as secondary hard drive in another laptop or machine?
0
votes
0answers
67 views

Ipsec connection fails between two hosts

I have two systems: Host1 (IP address - 10.1.0.1) and (Host2 IP address - 10.1.0.2) I configured IPsec on both machines as below: Host 1 config (/etc/ipsec-tools.conf) #Host 1 /etc/ipsec-tools.conf ...
0
votes
0answers
32 views

How to set up apt-get ssh transport with chroot

I want to set up a private APT repository that is only accessible by a shared public key, via the ssh transport. The only problem is, this also gives ssh access to the machine. I would therefore like ...
1
vote
0answers
43 views

Application Whitelisting

How does an Ubuntu administrator implement application whitelisting? For example, if I create a LAMP server and I only want SSH, Apache, MySQL and PHP to be able to execute. How can I prevent any ...