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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1answer
33 views

Do live (versions of) unix distributions ever automatically pick up config info from a OS already installed on the machine?

Maybe this is a silly question, the answer is probably no; but I gotta ask. For example, if I have an Ubuntu Live USB running on a machine with Ubuntu already installed, might the Live OS ever look ...
1
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1answer
165 views

Monitoring an under attack Server thorugh a remote endpoint

I have this Debian server that is constantly under attack as shown in its /var/log/auth.log file. I was wondering if there is a best practices of monitoring it through sending all important log ...
4
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5answers
2k views

Protect folder from sudoers

Is there an ability to not allow sudoers view your folder (only you and root can access folder)?
6
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2answers
1k views

Deleting users with nologin shell

On a security audit performed on our production Linux servers , we were asked to remove nobody user if no application are using it. I checked and could see that there are no files owned by 'nobody' ...
1
vote
1answer
115 views

Ninja privilege escalation problem

I have a problem with ninja. I think I have configured it correctly. However, when I type in su test to login as test and then run sudo -i the log shows that test is in the ninja group when in reality ...
4
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3answers
1k views

Securely feeding a program with a password

After understanding the problem with using a password in the command line, I need to find a way of feeding a program with a password without it being a problem (without the password being recorded ...
29
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3answers
3k views

Why shouldn't someone use passwords in the command line?

Why do people fear writing passwords in the command line? The history file is located in ~/.history, so it's available only to the user who executed the commands (and root).
2
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2answers
551 views

Does PHP exec() store the executed command anywhere?

Suppose I have the following code in a PHP web application. $encrypt ? $password = generatePassword($passwordstrength): $password=""; $estring = "7z a -p$password -mx0 packFoo.aes.7z mydir/foo"; if($...
5
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2answers
12k views

Allow a specific user or group root access without password to /bin/date

As the title would suggest, I'd like to give a user or group full root access to the /bin/date command, including any manner of arguments as defined in the man pages. I understand /etc/sudoers ...
2
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3answers
756 views

I have installed Linux distribution. Do I need to set root account or the user account is enough?

I have these credentials that I am using for logging in with my Linux distribution (Ubuntu 13.04) when starting the computer: james myawesomepassword123 I type the password on the login screen and ...
4
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2answers
499 views

Understanding getlogin()

I think the previous iteration of this question was a little bit like a carpet bomb of questions, so that may have turned people off to it (to the point of almost being flagged for removal) so I'll ...
3
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1answer
523 views

ufw firewall rules for security.debian.org

What is a practical way to manage a whitelist of firewall outgoing connection rules for http://security.debian.org (on a server that blocks all outgoing connections by default)? My understanding is ...
0
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1answer
4k views

fopen: $JOHN/dynamic.conf: No such file or directory

I have an unshadowed db.txt file: [root@SERVER ~]# rpm -qa | grep -i john john-1.7.9-1.el6.rf.x86_64 [root@SERVER ~]# head -1 /etc/issue Scientific Linux release 6.3 (Carbon) [root@SERVER ~]# cat db....
0
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1answer
72 views

Let pam module use hostname -s

Our hostname command gives back the servername.domain. This is in conflict with our authentication mechanism with our Active Directory. Is it possible to let the pam module use hostname -s (the ...
0
votes
2answers
119 views

are daemon tmpfs executables copied unencrypted to memory upon execution? (prevent if so?)

When a daemon is executed, is the executable copied to memory? If so, can it be copied encrypted? If not, is there a way to prevent the executable from being copied to memory? The executable is ...
2
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0answers
144 views

Understanding getlogin spoofing

My question is in three (or so) related parts: 1) My understanding is that getlogin() will effectively return the auid associated with the process and so isn't actually changable by the user. Is that ...
3
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3answers
3k views

Encrypting loopback images without using a loopback device

I'm trying to design a firmware update system for an embedded Linux system. My plan is to send an image that can be mounted on the target system, so I don't need to unpack the entire file. I also want ...
4
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2answers
2k views

Disadvantages to having www-data able to log in

I run a tiny web server basically just for hosting small data projects and files. This server has a public IP address. I would like to be able to FTP in and upload files directly to /var/www/*, and ...
0
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1answer
224 views

Iptable rule to ssh over the internet

I've a server abc.example.com and a remote desktop zzz.example.com. I'm using SSH over a custom port, say, 6789. Whenever my firewall is off, I'm able to connect to the server successfully. But, as ...
3
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3answers
1k views

Privilege escalation detection?

I am not a linux/unix expert but everytime when I read about some local privilege escalation exploit (e.g. this), I wonder if an OS can detect that there is someone logging in as root (or new root ...
4
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4answers
13k views

What type of permissions should a user's home directory and files have?

I'm working with a fresh install of Ubuntu 12.04 and I've just added a new user: useradd -m testuser I thought that the -m flag to create a home directory for users was pretty standard, but now ...
1
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0answers
59 views

ufw in laptop running Ubuntu

I installed ufw and enabled it. The status is: Status: active Logging: on (low) Default: deny (incoming), deny (outgoing) New profiles: skip But, I am able to navigate the web, get emails and ...
3
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1answer
453 views

How to lock-down input on a Linux machine?

We need to put out a web browser to a public place to show informations. I need to lock down all the input interfaces via software methods. So ex.: if someone plugs a USB keyboard to the machine it ...
0
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0answers
144 views

Installing Ossec on an existing centos 6.4 machine

I have an existing machine running centos 6.4. Is it ok to install now the Ossec or it's not worth any more as the machine is already running for few months. Which is the best mechanism to install ...
3
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1answer
2k views

Benchmarking Apache using ab

I was doing some performance testing for Apache using ab. Apache in our case is only working as a load balancer balancing load between two Liferay servers. Initially, I did the testing for 1000 ...
6
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1answer
273 views

Does fail2ban offer any additional protection to SSH if password login is already turned off?

I’m setting up a Debian VPS on Linode to use as a public web server, and I’m following their security suggestions. The last suggestion they make is to install fail2ban, to avoid dictionary attacks on ...
0
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1answer
414 views

How to generate 4 WEP keys with linux commands?

I have a sagem router. this router is able to generate 4 WEP keys from a given passphrase. Example: Passphrase: "hahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahaha" key1: ...
5
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1answer
2k views

Which home directory should 'nobody' have?

I'm messing around with Tiger security audits on my CentOS box, ensuring the server is fit for being online, well as close as it can get anyway. I noticed a warning about the user nobody having / as ...
3
votes
3answers
788 views

files in /proc/$PID (e.g. ssh-agent, Chrome) are not owned by user but by root

I am just answering another question here :-) and thus had a look – wanted to have a look at /proc/$PID/fd of ssh-agent in order to find out which socket it uses. But I can't. I am quite surprised to ...
1
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1answer
389 views

LAMP Server setup for personal development

I am setting up a LAMP server in VirtualBox for personal development. This will be an Ubuntu Server 12.04 install, and I will be using Virtual Hosts for Drupal, Yii, and other small PHP apps. Ideally ...
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3answers
532 views

Is there a way to 'authorize' a command typed in by a user?

is there a way we can authorize a command typed by a user before it takes effect? For example, when a user types cp file1 file2, the command will not be executed and a root / root-equivalent user ...
3
votes
2answers
403 views

How to make sure the shell builtin echo is invoked so that its not visible in process list?

Is this going to be visible in the process listing if the below line is executed from a command line or a shell script bash -c "echo $password" or i just need to do echo $password from within ...
1
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4answers
3k views

Is it possible to “hide” an account from /etc/passwd?

A typical Linux system has not only accounts for the actual user(s) of the system, but also various system accounts. Is there any file like /etc/passwd for daemons, or other means resources where an ...
2
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1answer
405 views

Nemo: Forget encryption password

I have mounted an encrypted disk by selecting it in Nemo (1.1.2), then typing a password. I can unmount the disk using Nemo, but now it can be remounted without requiring the password. Probably ...
1
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1answer
509 views

How to retrieve information about locked accounts

Is it possible to retrieve info regarding to locked unix accouts? I am interested in seeing information about what date and time the lockout happend and from what hostname (pc name). I would like to ...
1
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0answers
529 views

How to add my own created certificate authority to system trusted repositories

I was told that I can add my created CA to trusted repositories/authorities in my system instead of adding it from browser and configuring in in ssl.conf. Yet I can't find anything similar on the web....
11
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3answers
33k views

How to “close” open ports?

A few days ago I started to care a lot about my data security, I end up nmaping myself with: nmap 127.0.0.1 Surprise, surprise, I have lots of active services listen to localhost: $ nmap 127.0.0.1 ...
2
votes
1answer
748 views

Is it possible to specify groups in /etc/security/capability.conf?

I've been inspired to start playing around with Linux capabilities again, my pet project is to replace the setuid on a lot of the binaries and provide access to additional privileged utilities to non-...
2
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1answer
1k views

wpa_supplicant store password as hash (WPA-EAP with phase2=“auth=PAP”)

Is there a way to store my password in /etc/wpa_supplicant/wpa_supplicant.conf as some hash instead of plaintext? By "password" I refer here to the password used for phase2 authentification. I do not ...
0
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2answers
245 views

unable login solaris box

There is problem on my Solaris 10 box. It's not possible to access directly to the box, but via ssh from another box after 3 wrong entries of username/password to box then login prompt changes, at ...
4
votes
2answers
879 views

How to encrypt my system such that suspend to RAM works and is also encrypted

How can I encrypt my system (at best using lvm + dm-crypt/luks) such that suspend to RAM works and that everything is in an encrypted state when suspended to RAM?
2
votes
1answer
139 views

How can I use ForwardAgent with keychain, or detect a new login?

My scenario: I have Server A at home, and Server B at my parents house. I also have Laptop A and Laptop B at home. I do all sorts of strange ssh hops - I might connect Laptop A -> Server A -> ...
4
votes
2answers
4k views

Sign a module after kernel compilation

I've built a kernel in tmpfs, then I rebooted. Now I see a message when I compile the 3rd party module, NO SIGN [M] XXXX.ko How can I get it signed? The key pair generated during rpmbuild is lost ...
7
votes
4answers
363 views

Which data should be excluded from log files , error messages etc. if posted online?

What data should one erase from log files, error messages etc., if posting them as a screenshot so as not to expose sensitive information? As I have little knowledge about this topic, I can vividly ...
3
votes
1answer
753 views

Having the 'id_rsa.pub' file in my dotfiles public repo securely

So this is something that I'm wondering, how can I have this file in my dotfiles GitHub repo? I'm sick and tired of having to generate a new SSH key every time I'm on a new computer or re-install my ...
4
votes
2answers
8k views

How to find out out WHEN an user account was locked

With passwd -S user_name one can find out, if an account is locked, but is there a way to find out when it was locked and who it locked? Further links: http://serverfault.com/a/485760/78439 Disable ...
13
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1answer
372 views

Can entropy consumption at program start be prevented?

I use Knoppix (or other Live CDs/DVDs) as a secure environment for creating valuable crypto keys. Unfortunately entropy is a limited resource in such environments. I just noticed that each program ...
4
votes
2answers
130 views

Fully seperate two accounts without installing seperate operating systems?

Our class is finally installing Mint Linux on our machines. The problem is our teacher is scared that we'll play war games against the two classes that use the computers. His solution is to install ...
0
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2answers
878 views

How do I make PHP securely load files from the server root home folder on CentOS?

So I built what I thought would be this awesome reporting page in PHP that loads data from some CSV text files and creates nice Google charts and tables for our clients. I then thought it would be ...
6
votes
3answers
12k views

Check outgoing network traffic

In Ubuntu, how can I check what information is being sent through the network connection, what programs are doing it, and what sites is my computer connecting to? I am not paranoid about security, ...