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

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7
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2answers
215 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
15 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
138 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
13 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
22 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
30 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
12k 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
340 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
27 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 ...
4
votes
2answers
2k 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
69 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?
-1
votes
0answers
7 views

Creating and Sharing an encrypted drive and be able to access it from a network

I hope that question made sense! Here is what i am trying to do. i have an Ubuntu 14.04.1 server/htpc/desktop. I use it as cloud storage and to stream to my tablets. It has two physical drives and i ...
0
votes
1answer
16 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
208 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 ...
21
votes
1answer
71k views

How do I scan for viruses with ClamAV?

I installed ClamAV via Terminal (Ctrl+Alt+T) with: sudo apt-get install clamav but how can I scan for viruses?
0
votes
1answer
18 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
78 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... ...
25
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
69 views

Can I install all the hacking tools of KALI on Ubuntu12.04 LTS?

I want to know is there any way to install all hacking tools of kali on ubuntu 12.04 ? If yes then pls tell me how ? like sqlmap , nikto , john , aircrack-ng etc . Thanks.
0
votes
1answer
29 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, ...
21
votes
6answers
17k 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
34 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
8 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 ...
1
vote
0answers
12 views

How to config PORT KNOCKING on CSF ubuntu server and access it by linux?

I'm trying to run port knocking work on a CSF on a small VPS, i setup this: 1 - the result of csf first test ok 2 - TCP_IN = "53,80" TCP_OUT = "53,80,113,443" UDP_IN = "53" UDP_OUT = "53,113,123" ...
33
votes
4answers
11k 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
45 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
75 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
0answers
20 views

How can I use public-key encryption for luks?

I have been running luks with the following commands: $ sudo dd if=/dev/urandom of=/keyfile bs=1024 count=4 $ sudo cryptsetup luksFormat /dev/XXX keyfile $ sudo cryptsetup luksDump /dev/XXX And it ...
0
votes
1answer
19 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
35 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
31 views

Is bash safe yet on 10.04?

Running shellshock test from https://shellshocker.net/ on updated 10.04.4 LTS 32.bit says it is still vulnerable to CVE-2014-7186 and CVE-2014-7187 CVE-2014-6271 (original shellshock): not vulnerable ...
0
votes
0answers
23 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
11 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
26 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 ...
1
vote
4answers
1k views

cryptsetup - LUKS vs. Truecrypt [closed]

this question may already been made but I'd like to know how secure LUKS / cryptsetup is compared to TrueCrypt. What is the advantage and what is the disadvantage?
0
votes
1answer
35 views

Every installation on desktop asks for passwords that I never set in the first place

Everytime I boot up and try to log in using ubuntu, it asks for a username and password: which I have never set in the first place. So I log in under guest account. But when I try to change ANYTHING ...
0
votes
1answer
342 views

vmware player bridged does not work when on vpn

The problem I am having now is I vpn off from my job to a vpn provider. I then load my kali linux vm and connect to the vpn my security labs. I can run scans, enumerations etc. The problem is when I ...
0
votes
1answer
778 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 ...
0
votes
1answer
22 views

Can I make Apache more secure by removing read access from the others group?

It says in the Apache documentation security tips to set your server root directory and sub-directories to be owned by root, with a group of root and to not be writeable by non-root users. However it ...
2
votes
1answer
233 views

Setting Up Users and Permissions for a Multi-purpose Home Server

I have decided to repurpose an old grey box computer to be a combination NAS/home media server, headless torrent server, and minecraft server. I am using this both as a practical piece of equipment ...
5
votes
2answers
91 views

What are the reasons to have strong password at home?

For a typical home PC the security situation is following: No servers running, not even the SSH. Firewall is ufw running in simple mode: all outgoing allowed, all incoming denied. Torrents and DC++ ...
0
votes
1answer
18 views

Can program crashes during development affect my system's security?

I have been using Ubuntu for some time, and I loved it! I'm feeling way more safe now. But, I'm a Computer Science Student, and I have to code a lot. And I have been creating various codes, and it ...
0
votes
0answers
9 views

IPsec XFRM bridge

I am new to IPsec, am trying to learn about XFRM bridge acutely. But am not getting enough information around the internet. Can someone help me by providing informational data and links regarding XFRM ...
1
vote
1answer
29 views

Display PPA from which package will be downloaded during upgrade

I have many PPAs installed on my Trusty system. However, I feel that they might try to sneak packages into my system other than those which I include them in the first place. Technically, after adding ...
10
votes
2answers
752 views

How do rootkits get installed on to a ubuntu server?

I've seen a few posts on checking for rootkits but haven't been able to find any information on how they get onto a linux system. In particular if you exploit a bug in a php web site (yes I'm talking ...
0
votes
3answers
115 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 ...
1
vote
1answer
32 views

Security of Ubuntu downloads

When I try to download Ubuntu Desktop and try to save, it shows different URLs. What is the difference between these different URLs. Which is the safest one? ( eg. releases.ubuntu.com ; ...
0
votes
1answer
8 views

Account Restrctions

i have tried this : ALL=/usr/bin, !/usr/bin/passwd, !/usr/bin/su but not success. is it possible user with sudoers permission cant able to change any password except his own user account ?
1
vote
1answer
28 views

Uninstalling Desktop sharing programs

Sine I want the most security as possible, I'm removing some programs that could give the access to remote desktop. In this case, I removed the Remmina Desktop Client (I think, if it comes with ...
0
votes
0answers
22 views

A question about logs (security)

I was taking a look on this page, about knowing if I'm being hacked, but I got a question. It says that: If large chunks of time (more than 5 minutes) are unaccounted for in a log file while the ...