Content related to computer security., i.e. content about policies, mechanisms, etc. needed make sure data is not leaked or corrupted and services available in all circumstances.

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2
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3answers
1k views

How can I securely login remotely to my Linux box over the internet?

I'm pretty much a Linux beginner, but this question has been on my mind. What's the simplest, most secure way to connect to my computer at home from work or from the library, &c? I'm running Mint ...
2
votes
2answers
1k views

Moving a root directory to a separate partition

I'd like to create a new partition and move the contents of the /var directory to it for the security reason of having /var/www and other subdirectories "mounted" with nosuid, noexec, and nodev ...
1
vote
1answer
1k views

add members of wheel group, sudo access

On Fedora15, following this wiki, I added a user to wheel group, which is already in the sudoer config file. but still I get not-a-sudoer error prompt. Should I specifically name every member of a ...
31
votes
4answers
30k views

What is the point of sshd “UseDNS” option?

I know what it does, but i don't know why. What attack(s) does it prevent ? Is it relevant for all kind of authentication methods ? (hostbased, password, publickey, keyboard-interactive ...)
0
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4answers
740 views

securing SSH and disabling direct root

In these instructions below what appears on my terminal is different so not sure what I should change. After port 22 mine says #AddressFamily any and further down for protocol it has longer line ...
0
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0answers
78 views

Usage of stunnel for configuring secure services as a default?

Ok, I am aware nothing will beat manual security configuration through your standard daemon config files, but is it bad practice to configure stunnel for all services on say, a production ...
-2
votes
2answers
116 views

What software(s) should I install on new system(with Linux as a OS) to prevent it from getting hacked? [closed]

I am switching to new system with a OS using Linux.I will be using another system which has windows ultimate which is hacked.I am being cyber bullied. I have given a reference to this as a question on ...
2
votes
0answers
3k views

How can I connect to a wireless network with hidden SSID using the terminal? [closed]

I'm starting to learn about wireless pentesting with BackTrack, and while learning how to find out the hidden SSID I wondered how could I connect to the wireless network after I discover the SSID. The ...
12
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6answers
53k views

How can I monitor all outgoing requests/connections from my machine?

My machine is a server so I want to ignore connections being made to my server (e.g. when someone visits my website). I want to see only connections/requests being made by my server to other places. ...
3
votes
1answer
76 views

How is the inherited file descritor vulnerability dealt with in Unices?

Ulrich Drepper describes a vulnerability in programs that have open file descriptors then they fork() and execve() without lots of very careful locking in place. He also talks about new kernel ...
3
votes
2answers
859 views

Is TRESOR included in the latest kernel?

Did TRESOR get included in the mainline Linux kernel? Where would I look to find out? Is there any documentation describing its use? Reading about cold boot attacks on Wikipedia makes me think TRESOR ...
1
vote
1answer
320 views

How to export a private PGP email key

I have made a keypair for my email address using gnupg. I thought that I should probably keep a backup of it so that if I lose my desktop computer I can continue using the same key. Is this the ...
0
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1answer
213 views

Intruder nature detection by opensource tools like tripwire

I want to use different kind of intrusion detection tools like OpenSource Tripwire. Please suggest me some tools which can provide me some additional information to that provided by tripwire? ...
2
votes
2answers
79 views

Checking integrity of my server data

I want to make a log to detect the nature of intrusions into my Unix/Linux based server. For that I want to learn some tools like Open Source Tripwire and OSSEC. Please suggest to me similar tools. ...
1
vote
1answer
2k views

Is there a way to report incorrect login attempts in Ubuntu 12.10?

I am concerned with some people trying to access my laptop while I am away in my work place. Therefore I was wondering if is there a way to set up kind of automatically monitor and report wrong ...
3
votes
1answer
1k views

How to replace setuid with file-system capabilities

Inspired by this question here is the follow-up: As some of you may know setuid-binaries are dangerous, since some exploits use these to escalate their rights up to root. Now it seems that there has ...
2
votes
1answer
141 views

is it secure /not dangerous to ssh with keys through public transparent proxy?

I use pub key for ssh. Is it normal practice to connect to own server through public proxy? I think with plain pass it is surely dangerous but how about RSA keys?
4
votes
3answers
1k views

Stracing su and ssh shows the password. Is this a security flaw or am I missing something?

I'm currently fascinated by strace so, being new to it, I decided to play around a little. As suggested by the question title, I tried both strace su and strace ssh. Both commands displayed the ...
4
votes
3answers
1k views

rsync server/daemon security

I have a NAS (Netgear Readynas NV+) at home and a linux (Arch) box at work that is always on. The linux box is already running an ssh server/daemon and the NAS is already running an rsync ...
2
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0answers
211 views

How many rings does OpenBSD use?

Usually a Windows/Linux operating system uses afaik max 2 rings But how many rings does OpenBSD use?
3
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1answer
3k views

How to ensure that anonymous FTP has been disabled on a Solaris 10 system?

What line in which configuration files in the /etc/ftpd directory do I have to check to ensure that anonymous FTP has been disabled? From my understanding now, to ensure that anonymous FTP is ...
1
vote
0answers
92 views

Running Tomcat MySQL and Apache under a group

I am trying to set up a web server at home using Ubuntu, but prefer my bash scripts to be platform agnostic hence why I am asking here. I also dislike apt-get everything. I am trying to create a ...
5
votes
2answers
415 views

What does “Do you expect to run the X Windows System?” do when installing OpenBSD?

When installing OpenBSD 5.1, I got the question: Do you expect to run the X Windows System? What change does the installer make to my system if I say "yes"? I know what X Windows is, but I don't ...
2
votes
1answer
355 views

How to move the /var/www directory to a USB HDD?

I have a default OpenBSD 5.1 install. How Can I enabled httpd, OK. QUESTION: How can I use the /dev/sd0a on /mnt/usbhdd type ffs (local, nodev) instead of the default "/var/www" directory? What ...
5
votes
2answers
896 views

How to disable login for an user?

My Linux has many not-human users like cron, ntp, daemon, http, etc. I want to disable anybody to login as any of this users. Real people on my machine are root and me, so only root and me should be ...
5
votes
3answers
290 views

Are sudo and gksudo safe?

I noticed after running a sudo command in terminal or running a administrative application that uses gksudo, it won't ask again for the password for a time (something like 5 minutes). Now let's ...
3
votes
1answer
1k views

How to disable remote access on a linux distribution?

So I've read in Mark Sobell's book on Linux, that Linux by default is open to remote administration. Now seen as I'm running a Fedora 17, on a laptop I never have to administrate anything on remotely, ...
5
votes
1answer
742 views

What are EXT4 Security Labels?

During Gentoo installation of Gnome keyring, I am told to switch on EXT4 Security Labels, which is described in the kernel documentation by: Security labels support alternative access control ...
3
votes
2answers
358 views

why slight delay after failed login in tty [duplicate]

Possible Duplicate: Why a wrong password gives a big delay Whenever I mistype my password when logging in in a tty, I have noticed that I have to wait for a second before I'm able to log in ...
8
votes
1answer
207 views

How to use /etc/fbtab in OpenBSD to secure X11?

OpenBSD's man page afterboot(8) suggests: "You might wish to tighten up security more by editing /etc/fbtab as when installing X." How might one do this? What lines when added to /etc/fbtab would ...
6
votes
2answers
5k views

Iptables: matching outgoing traffic with conntrack and owner. Works with strange drops

In my iptables script I have been experimenting with writing as finely grained rules as possible. I limit which users are allowed to use which services, partly for security and partly as a learning ...
3
votes
1answer
512 views

Why is it a bad idea to run as root? [duplicate]

Possible Duplicate: Concern about logging in as root overrated? I often hear that it's a bad idea to use root for general use. Why is this a bad idea?
2
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1answer
239 views

Security drawbacks of disabling tty password check

I found that, in /etc/inittab, this modification (-a username) for the user u disables the login/password check for all tty:s: 1:2345:respawn:/sbin/getty -a u 38400 tty1 2:23:respawn:/sbin/getty -a u ...
1
vote
1answer
308 views

For an init.d startup script, what is the ideal user to use as the owner of that process

Everyone says that running processes as root is bad, since it defeats the security and privileges model. But what user should be used to run a startup process? Is it really necessary to create a new ...
5
votes
1answer
757 views

root owned program with setuid bit on

Ping is a a program owned by root with the user id bit set. $ ls -l `which ping` -rwsr-xr-x 1 root root 35752 Nov 4 2011 /bin/ping As I understand it, if a user runs the ping process, then the ...
0
votes
1answer
78 views

What to make of system scans reported by psad

My system logs show that psad detects scans like this every minute. psad: scan detected: 192.168.1.10 -> 192.168.1.1 udp: [53] udp pkts: 2 DL: 2 If the first address is mine, and the second ...
5
votes
1answer
190 views

OpenBSD and limiting login to local only like in FreeBSD's login.access(5)

I am using OpenBSD as my desktop. I don't want to login to my machine remotely, and I don't want anyone else to login remotely. In FreeBSD there is a file called login.access(5) that can be used to ...
0
votes
3answers
155 views

Is it possible to have malware software in Linux without executing untrusted applications?

I'm linux user and I'm thinking about it's vulnerabilities to malware. Can I get any malware if I run only trusted applications from distro's repository?
1
vote
2answers
436 views

Need advice on using Wireshark + aircrack-ng

I am making acquiantance with wireless security and attacks and was told to run some tests with aircrack-ng and wireshark. So I installed both of them and ran airmon to switch wi-fi card to monitor ...
1
vote
0answers
1k views

Symbolic link to a socket

From a security point of view, is it safe to create a symbolic link to a socket file? The following bits of context refer to the deployment of a web application on a shared hosting service. $ ls -al ...
5
votes
3answers
313 views

Effectivity of shred on different file systems

man shred warns that the command is not useful on file systems that don't overwrite in-place. I don't have much knowledge about the current and upcoming file systems, but I would suspect that many of ...
4
votes
2answers
335 views

Shredding everything: files/folders and corresponding filenames

Using find, it is easy to shred a directory's contents recursively (as discussed in this question). However, sometimes the filenames on their own carry sensitive information already. Is there a way to ...
2
votes
2answers
863 views

Chroot Risks w/ /dev and /proc

I am planning to set up a few chroot jails for some users to run/test Java applications (lets just assume each application is untrusted). Is there any risk involved with mounting /dev and /proc into ...
2
votes
1answer
211 views

How do I ensure outbound TCP/IP traffic always uses a VPN, even when using Wifi?

I'd like to ensure that my VPN is started and running, before any TCP traffic from any of my background services send or receive data. How can I guarantee that this is the case? How do I handle ...
0
votes
2answers
1k views

What does “0” mean in the owner and group permission lists of a file/folder?

The question is in the title. What does the number 0 signify?
6
votes
1answer
693 views

/etc/passwd sql with bash access

I just got a CentOS VPS and was reviewing the passwd file and saw this: mysql:x:498:499:MySQL server:/var/lib/mysql:/bin/bash Is bash necessary for mysql?
0
votes
1answer
183 views

How to use linux tools to verify a site's authenticity

When I go to certain websites where it's important for me to know that I'm connected securely, certain browsers will say that the site failed the authenticity check. Firefox won't say anything, but ...
1
vote
1answer
1k views

SSL handshake failure with Shibboleth [closed]

I am using Shibboleth for single user authentication and it needs a ssl configuration which facilitates the user authentication process. Before it was working fine but now I am facing a SSL handshake ...
2
votes
2answers
196 views

How to securely export a device (HDD)?

So I have a Scientific Linux 6.3 (RHEL clone so basically the question is Redhat related) machine called "B" (with an extra "A" HDD besides the system HDD) and a notebook with SL 6.3. They are in a ...
3
votes
3answers
111 views

Stop user being able to access live CD environment or recovery mode?

I'm haved created an account on ubuntu that is just a standard user but with no internet access. I have also removed 'recovery mode' from the grub menu so that one cannot just choose this option ...