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

learn more… | top users | synonyms

4
votes
2answers
82 views

How to prevent users from deleting files that are already in use?

Consider this scenario: User is executing a command on a file. This file becomes 'in-use' now. $ tail -f somefile.log In another shell, user deletes the file. $ rm somefile.log Now, this file ...
0
votes
0answers
10 views

Camera Monitor keeps triggering

Just installed Firefox into WINE and now webcam-monitor keeps saying something is accessing my webcam. What's going on?
2
votes
1answer
52 views

Are any Ubuntu (Linux) vulnerabilities in media applications?

Ubuntu (Linux) has a solid system that permits and requires root privileges to modify the system. However; if an installed application eg. VLC, audacious, some image viewer installed from the ...
0
votes
0answers
7 views

Matching vulnerabilities with upstream versions

How am I supposed to match vulnerabilities with services fingerprint with ubuntu (and debian) upstream's version? Is there a public database to match these versions with original versions? ...
0
votes
0answers
9 views

What prevents a user process from writing at random positions in memory and damage the OS or other processes?

Why can't the following code damage memory? int x; while(1) { x = rand();//assuming that the address space has the size of an int *x = 0; } I know that each process has a virtual address ...
0
votes
0answers
16 views

How can I limit Symform's privileges?

Symform's services expect to be run as root. For example, when I override what user runs them, they fail with errors such as: mv: cannot move '/tmp/symformtasks.98145' to '/etc/cron.d/symform-node': ...
0
votes
1answer
46 views

ubuntu 13.10 - not prompted for login at start up

Mostly - oddly not every time - when I reboot, or start up my laptop, I am not prompted for a password; it goes straight into my desktop. I don't like this one bit. There are other users on my laptop, ...
0
votes
0answers
54 views

Should I install Apache & PHP separately OR uninstall MySQL from a LAMP stack?

I'm developing a site for my customers to view their account transaction history, with the ability to make payments through a hosted pay-page. Our legacy system requires keeping our database ...
0
votes
0answers
10 views

How to save kftpgrabber site in kwallet

I'm researching for a more secure FTP client which is more securelely stores site details like passwords, than Filezilla and found kftpgrabber fits with my need. However for get the most out from ...
18
votes
3answers
1k 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 ...
0
votes
2answers
37 views

Is the latest provided php5 package in an LTS distribution secure?

I need to update php5 on a 12.04 LTS production server. The latest candidate provided is 5.3.10-1ubuntu3.9. Is that version patched to be secure for use in a production environment? PHP is up to ...
1
vote
1answer
27 views

how to limit resources to a shared ubuntu 10.04

The title might not be explanatory enough but I couldn't find any better way to formulate it. I will be running a server for office use. It will host applications on tomcat. 2 differents people would ...
0
votes
0answers
33 views

Is it safe to run Samba on a wireless network?

I have Samba server set up on my laptop so that I can share and sync files between the laptop and my Android device through a WPA-secured wireless hotspot (which is provided by laptops wireless card). ...
1
vote
1answer
128 views

Man in the Middle Attack warning with OpenVPN

When using openvpn --config /home/xxx/vpnbook-uk1-udp25000.ovpn I always get this warning: Sat Feb 22 11:16:04 2014 WARNING: No server certificate verification method has been enabled. See ...
0
votes
0answers
28 views

How does security differ between any two standard users?

If we take two standard users, so ignoring admin/sudos, are the security limitations between one user and another down to their respective file permissions? So what Alice can do in the system vs ...
6
votes
1answer
271 views

What are the risks of running Nautilus as root?

Whenever I try to access files outside my home directory I get a permission error. People keep recommending running Nautilus as root by running the following commands in a terminal: sudo -i nautilus ...
0
votes
1answer
102 views

mysterious files and possible virus on ubuntu 12.04.2 server

IT services at my institution discovered our server sending out SPAM emails and flagged it as compromised. Further investigations suggest that it is indeed infected with a virus. For instance, there ...
0
votes
0answers
21 views

OpenPGP smart card fails after card reinsertion

I am expirimenting with an OpenPGP smart card. Things work great except for the following: Plug in smart card and turn on computer "gpg --card-status" shows the card Everything works as it should ...
1
vote
1answer
309 views

How to secure postfix on Ubuntu Server

I am setting up a new VPS server with LEMP. The only piece missing now is the mail server. Do I need to do something special to make it secure? or it is already secured when the installation is ...
0
votes
0answers
18 views

NIC in Monitor mode used by two program simultaneously

Presently I am designing sniifer that is uses NIC in monitor mode but side by side I am also using wireshark ( for which also NIC in monitor mode ). So both this program using monitor mode ...
8
votes
5answers
2k views

Rename /etc/passwd and /etc/shadow for security reasons [closed]

I have a server. My server is secure, but let's imagine a good hacker that enter in. He can now look into /etc/passwd and /etc/shadow. I would like to rename that files /etc/passwd to something like ...
0
votes
2answers
354 views

How can I scan for possible viruses on my Ubuntu system? [duplicate]

I think I may have a virus. How would I go about checking for a virus and how can I protect my computer from any other virus? Please give detailed answer as I'm still learning about Ubuntu.
1
vote
2answers
107 views

Am I under attack?

When I checked my log viewer, I noticed that ufw is blockng many ips that I'm not familiar with! I have only three computers in my local network at the time when I was checking my log viewer I was ...
10
votes
2answers
119 views

Are all Ubuntu update download servers HTTP only?

In Update Manager's software sources, the option exists to choose a download server and protocol like shown below. Do all updates download via HTTP only? And if HTTPS (or SFTP) aren't supported, why ...
2
votes
1answer
284 views

Virus detected with ClamTK (Possible infection?)

I did a routine scan of my system, with ClamTK. The the anti-virus reported 3 detections. The names of the three detections are: 1.[PUA.Phishing.Bank] 2.[PUA.Phishing.Bank] 3.[PUA.Script.Packed-1] ...
0
votes
0answers
7 views

comparing certificates in firefox

I need to compare the google-mail certificates of firefox browser while connecting to the google-mail server (its a demand cause i'm building a customized system for my clients) i know firefox does it ...
0
votes
0answers
1k views

How to setup Squid Proxy Server on ubuntu 12.04 LTS?

I had tried using the ubuntu wiki guidelines to set it up on test server, and it worked. Though I would appreciate if anyone can provide me with few other links as this time I am going to install it ...
4
votes
1answer
188 views

Web server atacks

I have a server (vps) to use as a repository and testing (gitlab and redmine) server. However apache crashed, seeing the /var/log/apache2/error.log have many errors of this type: [Fri Jan 31 ...
0
votes
0answers
11 views

Are Key files for repositories fetched over HTTPS?

I'm connecting to the internet through a public internet connection. I want to know if some one can do a MITM attack and give wrong Keyfiles when I update and upgrade. The difference here would be ...
0
votes
0answers
13 views

is it possible to to use ssmtp with PSAD

I have been searching online and I haven't seen yet a way to use PSAD with the simple ssmtp. I would be grateful if anyone can share a link or shed a light on configuration. I believe it will be an ...
0
votes
0answers
13 views

is denyhost central database stored locally?

I was tasked to write a security policy to apply to any ubuntu server we deploy at a client's site. Knowing how some of the corporate are restrictive on what resource is available to what box on their ...
1
vote
2answers
40 views

Network Information for Theft Prevention

I haven't seen much of this around, and I'm not a network expert/sysadmin, so I need some advice. I have a laptop that I'd like to "protect" against theft (this is really a game more than a real ...
3
votes
1answer
73 views

Found a hidden port . . . what now?

I ran rkhunter and found an open hidden port. How do I close a port that is not listed with the netstat or fuser command? It is hidden from these which is why it was flagged. Aside from blocking the ...
0
votes
0answers
17 views

How do I grant UFW manage access to a particular user?

I would like to allow a particular user the permission to run "ufw allow" (or equivalent). Ideally without giving that user the ability to run other privileged commands, or give firewall authority to ...
23
votes
1answer
643 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?
0
votes
1answer
33 views

Is it possible to create a locked down 'dumb terminal' with ubuntu?

My company has a large amount of document review work that must be done manually by temp workers. The work is done on our website, accessible via VPN only. We are planning to just show scanned images ...
6
votes
1answer
77 views

Disallow user access to microphone

Blacklisting a kernel module would disable the microphone for all users. I have set up a restricted user, who should not be able to use the microphone. The restricted user should, however be able to ...
1
vote
3answers
91 views

How can I create a hardened Virtualbox image for PenTesting?

As a serious security researcher, I'm looking for an answer to securing a ubuntu installation against unwanted intrusion. This should include how I can: log and alert remote connection attempts Log ...
3
votes
1answer
2k views

Ubuntu - saying your security settings have blocked an application from running with an out-of-date version of java

I have this new problem since 2014 begin. I cant remotely login to this enterprise network for giving them support. Its keep showing this new error. How to fix it please? EDIT:
0
votes
2answers
2k views

How to install up-to-date virus scanner ClamAv in 12.04? [duplicate]

ClamAV is in the official security software repositories from Canonical, but on running freshclam, it reports: ClamAV update process started at Tue Jan 21 10:31:59 2014 WARNING: Your ClamAV ...
0
votes
1answer
760 views

How to get Avast! Running on Ubuntu 13.10

I know in the current time, anti-virus isn’t exactly needed for Linux,however I still wish to install some form of protective layer. I had previously downloaded a .deb for the installation of Avast! ...
11
votes
1answer
215 views

Strange POST requests to my Ubuntu server - am I in trouble?

I have an Ubuntu Server 12.04 installed on a VM. This server has apache2-mpm-prefork and libapache2-mod-php5 installed. I was looking through the logs and recently came across these rather ...
0
votes
1answer
48 views

Ubuntu One-related question - How to share files securely?

I have procrastinated this question a lot because I know it is a complex and a "crossover". That's why I have hesitated if to ask it here, on Ask Ubuntu, or somewhere else, let's say, Freelancer or ...
1
vote
2answers
1k views

Help! My server has been hacked - .IptabLes and .IptabLex in /boot [closed]

I'm running a Ubuntu 6.06 dapper server and it has been hacked. I'll admit up front here that I'm a programmer and not a system administrator so even though I've worked with Unix/Linux for years my ...
1
vote
1answer
80 views

What is a TCP wrapper and how do I use it? [closed]

What is a "TCP wrapper", and how can I use it to improve system security?
1
vote
1answer
29 views

Unsecured desktop sharing

Can anyone advise me of the best way to get around mongrel hackers. I came home to find my mouse pointer merrily moving across the screen, opening disgusting web pages and what looked like trying to ...
6
votes
3answers
445 views

How safe is it to transfer sensitive information over Tor Browser Bundle on a restricted network?

I am using the Tor Browser Bundle in Ubuntu from a client machine on a restricted network. In part, I do this because it appears that TBB's native encryption allows me to bypass certain network ...
0
votes
1answer
84 views

is adobe flash player plugin installer marked as “important security update”?

Why is adobe flash player plugin installer marked as "important security update"? Is security really compromised if one does not install that?
1
vote
1answer
76 views

How vulnerable are you by installing a desktop on Ubuntu Server? [duplicate]

I've read around that installing an Ubuntu desktop on top of an Ubuntu Server provides security holes and performance issues. But I can't find anywhere as to describe what security holes would develop ...
2
votes
1answer
228 views

How to protect my PC from netcut users? (ARP spoof)

In my campus, some people they are using netcut in Windows and they are blocking us not to use Internet. Since I am a Ubuntu user, I can't install neither nutcut nor netcut-defender to protect and ...