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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1answer
42 views

What is the difference between the FreeBSD flags, immutable and unlink?

What are the differences or similarities among the FreeBSD flags, simmutable/uimmutable and sunlink/uunlink? Reading man chflags, I see these flags: schg, schange, simmutable set the system ...
1
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0answers
64 views

nmap doesn't detect opened port [closed]

I'm testing some vulnerabilities on a machine which has the port 22333 opened (it's used as the ssh port, and I can connect to it without any problem and I can get connected as well with the telnet ...
2
votes
1answer
122 views

Using mailx without storing a password

I'm trying to setup mailx to use my Gmail account. I've found a configuration that can send mail successfully but it requires me to store my email password in a configuration file in my home ...
1
vote
2answers
89 views

iptables configuration - ssh connection only from a remote network

I'm trying to configure Iptables of a server in order to permit SSH incoming connections only from a certain network. by the way this is the rule chain : # Drop anything we aren't explicitly ...
1
vote
2answers
39 views

OpenVPN : protect your clients key/cert/conf from being stolen?

I have configured an OpenVPN install. Mode: multiclients 1server. Clients are raspberries. I note how easy it is to steal a rasp, and look in HDD to get key+cert+conf. Copy it on your laptop, and ...
8
votes
3answers
1k views

Is it a good practice to run a daemon under a non-root user account?

I've developed an application that uses NTP to change the network time, to sync two of my computers. It runs as root, since only the latter is allowed to change the time and date on Linux(I guess). ...
0
votes
0answers
21 views

Where to put the ASCII WPA2 Wifi Key in MacOS X?

I tried to make some research about wifi security in our company: So i tried to het WPA2 Wifi key using wifite tool in Kali linux distribution. After the few attempts i get WPS PIN and WPA2 KEY: ...
0
votes
1answer
48 views

What are the best practices for permissions and and methods for generally avoiding using sudo? [closed]

The main point is that I only want one user to have sudo access - really only for use in set up and emergencies. I don't even trust myself with sudo access all the time. Are there best practices ...
1
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0answers
52 views

What is the best operating system for beeing anonymous [closed]

Im looking for an anonymous distribution of linux, anyone can help me? Thanks
2
votes
1answer
90 views

How to safely transmit a password over SSH for a remote command to use

On the local server, I have a program that stores the password in the predefined environment variable (SPECIAL_PASSWORD). On the remote server I have a program that reads and uses a password from a ...
1
vote
0answers
28 views

Is there any considerations I should take when running untrusted apps as non-root user?

I have to use an application I don't trust (unstable) and I will run it as a non-privileged user so if something bad happens the damage would be limited to the home folder of that user. I removed ...
0
votes
4answers
128 views

How to track/log commands executed on a shell?

Can commands be written to a logfile before they were executed in any shells? I know there is a patch for ssh to log all commands from ssh sessions, but i want to log even commands executed from a ...
5
votes
1answer
79 views

How to enable random PIDs on Linux?

I'm currently comparing random PID implementation on OpenBSD, FreeBSD and Linux from security perspective. As long as OpenBSD and FreeBSD are concerned, my work is done. However, while the answer ...
0
votes
0answers
45 views

Use sudo as login

I've picked up the habit of using sudo and disallowing root logins. In cases, sudo is integrated with GUI configuration tools that require it. Are there any serious efforts to replace login and ...
5
votes
1answer
126 views

Is it safe for my ssh user to be given passwordless sudo for `apt-get update` and `apt-get upgrade`?

I have an SSH standard user account on my personal server, and it has sudo access (via its password). I ssh in using a public key, so I don't have to type in the account password to log in. Is it ...
2
votes
2answers
111 views

How can I allow SSH and SMTP only using IPTables?

I've got a raspberry pi set up to send me periodic emails. As it's connected to the internet 24/7, I need IPTables set up properly. I want to allow incoming SSH and allow emails to send out on port ...
1
vote
1answer
37 views

Script samba password but securely

I want to script the addition on a samba user and the password. I have seen solutions similar to the one here Piping password to smbpasswd echo -ne "$PASS\n$PASS\n" | smbpasswd -a -s $LOGIN but ...
1
vote
2answers
44 views

How can I create an SSH login that delegates to telnet securely

I'm playing around with the idea of creating a MUD, but one of the down sides is that they use "telnet" which is insecure. I'd like to retain the ability for "anonymous" users to access a specific ...
4
votes
1answer
42 views

Monitoring ARP Poisoning

How to monitor ARP poisoning? These few days my internal website that can be accessed locally has weird image replacing every images on the site for few seconds (it got back to normal after ...
4
votes
1answer
132 views

Unexplained files found in home folder

For background information, I'm running openSUSE 13.2 and KDE 5. Today I found a number of unexplained files and folders in my home folder which state they've been edited 3 days ago. I do not ...
1
vote
0answers
52 views

Allowing sudo kill for remote user for recovery purpose. Security implications?

I'm planning to create user allowed to SSH in and with right to sudo kill in case something disables local terminal/keyboard/display etc. Would probably add ps and/or htop to the list, as well. I ...
1
vote
2answers
146 views

Too many open ports in Debian 8

The IT department has given me 3 virtual servers with Debian 8 for my area, which I will manage (but they have some monitoring tools). Starting Nmap 6.40 ( http://nmap.org ) at 2015-05-11 13:33 ART ...
2
votes
3answers
62 views

Does a Certificate Authority represent my company or a server?

I am setting up my second OpenVPN server with TLS and so I have a question about CA. Should I create a separate CA for each server or use the same? Why? Both servers will cater to the same network ...
4
votes
2answers
123 views

how to prevent a buffer from swap

this question is specific to Unix and Linux. but it is programming and security, too. my program will get a clear password or decryption key by one of a few ways (decrypting a password file, asking ...
1
vote
0answers
35 views

Multiple DHCP Offers - Which is selected? [closed]

I have created a testing scenario in VMWare for a man in the middle attack using DHCP spoofing. It's for a college project. Windows 8 machine bridged to host adapter Kali linux bridged to host ...
0
votes
1answer
44 views

What are the differences between sudo and the use of groups?

I know these are tools used for improving security. But what I would like to know is what they are and how they work?
2
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0answers
132 views

Where to put the SElinux policy to allow acpid shutdown the system?

I'm using Centos7 minimal. I've installed acpid and the daemon is running. When I hit the power button, I get the following in /var/log/messages May 2 18:52:53 localhost systemd-logind: Power key ...
0
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0answers
101 views

logging wrong passwords in /var/log/auth.log

/var/log/auth.log logs (among other things) failed login attempts to my debian linux. I was wandering if it is possible to ask it to log the password that was used in the failed attempt. This is ...
6
votes
3answers
150 views

What bad things could happen if we don't use sudoedit?

We know it's safer* to use sudoedit, but what bad things can happen if we have the following in sudoers? Cmnd_Alias FOO = /bin/ed, /usr/bin/ed, /usr/bin/vi foouser LOCALHOST = NOPASSWD: NOEXEC: FOO ...
-2
votes
2answers
42 views

Can I restrict the root to a single browser?

I want to be able restrict myself to firefox. I do not want to be able to use any other browser. So if I install chrome or any other browser, I don't want them to work on my Linux machine. Here is ...
0
votes
1answer
49 views

What changes my boot partition and how to prevent it?

As an another countermeasure against security threats I wrote a little script that computes MBR and boot checksum and then compare it to the old one. As long as the computer is running this is OK, but ...
2
votes
1answer
132 views

Understand HMAC authentication in case of site-to-site OpenVPN tunnel

I have a very simple OpenVPN setup where OpenVPN server is started with openvpn --ifconfig 10.10.10.1 10.10.10.2 --dev tun and client is started with openvpn --ifconfig 10.10.10.2 10.10.10.1 --dev tun ...
2
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0answers
95 views

Security of sudo not asking for a password after the first time

After using sudo and entering a password to do so, sudo remembers that we have entered a password and we do not have to enter a password the next time we use it. I am concerned about the possibility ...
0
votes
1answer
78 views

How can I study Linux, in and out? [closed]

My team and I will soon begin studying and practicing for the nation-wide Cyber Patriot program. As I'm famed for being our "Linux guy", I would really like to improve my knowledge on the subject. ...
0
votes
1answer
48 views

UNIX Account management

Would like to know if there's some opensource solution aimed to manage and administer system authentication and RSA keys for staff, contractors and clients across the organization. My systems to ...
1
vote
1answer
35 views

Where to verify and review various packages before installing them

I am new to Unix/Linux and corrently setting up a Debian Wheezy server for my domain name. Here and there I find useful tutorial on how to do this-and-that, but I am not sure where I can find a ...
2
votes
1answer
97 views

How to scan a directory with a space in its name with maldet

I'm trying to scan some directories with Linux Malware Detect (command-line command maldet): maldet -a /SOMETHING\ 1/ But I get: maldet(13857): {scan} invalid path /SOMETHING 1/ I've tried ...
2
votes
1answer
298 views

Exploit FOUND with clamav on Fedora 21 in Oracle's java

I'm scanning one of my systems with Clamav like this: $ clamscan -r -i --remove --max-filesize=4000M --max-scansize=4000M \ --exclude=/proc --exclude=/sys --exclude=/dev ...
4
votes
3answers
183 views

Remove passphrase from private key and set specific file mode

If I set a passphrase on my private key like so: openssl rsa -des -in insecure.key -out secure.key and I remove the passphrase like so: openssl rsa -in secure.key -out insecure.key then my ...
0
votes
1answer
32 views

Sanitise bash arguments

I have a script which takes user input and does a lot of things. One thing which I am worried about is it takes a file name and removes that file. e.g. rm -rf $arg1. A user could technically input / ...
1
vote
1answer
65 views

wheel groups and permissions

I'm new to a lot of things Linux, so this might be basic stuff. We're thinking about setting up a wheel group and removing permissions from root. Not even sure that's possible. We are having a ...
0
votes
2answers
687 views

How to import the official Tor GPG keys?

I am trying to install the latest Tor Browser Bundle on Arch Linux: $ makepkg --syncdeps --install [...] ==> Verifying source file signatures with gpg... tor-browser-linux64-4.0.8_en-US.tar.xz ...
1
vote
1answer
106 views

LDAP Force Password Change Through HTTPS

We have a "master" server running Suse Enterprise with LDAP that controls user's access to our systems. We want to implement a 90 day expiration policy, but the issue is that most of our servers are ...
1
vote
2answers
33 views

How do I install programs in /usr/local if they shouldn't be compiled by root?

Somewhere in the back of my brain is the memory of reading a cautionary internet voice warning against compiling (i.e. running make) as the root user. Perhaps it's something like this story ...
0
votes
0answers
36 views

Bro-IDS CSV conversion

I have Bro-IDS currently operating under Centos 7. I need to convert the output to CSV format. The documentation that I have seen on this is not clear to me. Has anyone done this successfully? I have ...
0
votes
0answers
37 views

Snort alerts analysis (web interface)

I have a question about Snort (or maybe any other IDS/IPS, any working solutions would be ok). The goal is to set up some web interface providing a way to view the whole TCP stream packets of each ...
2
votes
0answers
26 views

Unable to use wifi card after putting it into monitor mode

I'm trying to monitor 802.11 Reauthentication requests and responses made from the DS to the STA. The problem is when using airmon-ng to put the card into monitor mode, the interface is no longer ...
1
vote
1answer
80 views

Dubious entry in logwatch

Today I found the following in the daily logwatch of my debian server: --------------------- Connections (secure-log) Begin ------------------------ **Unmatched Entries** sg: user 'root' (login ...
2
votes
0answers
19 views

Tails OS:Network Filtering Syntax to Allow I2PBrowser to listen at localhost:6666, Then Allow TorBrowser User to Connect to it

I've had a bit of experience in Linux, but I'm still learning and brand new. I've been able to proxy Tor right into I2P on a normal Debian Wheezy installation successfully. My process involves ...
0
votes
2answers
94 views

SSH authenticity couldn't be established

Last night I SSH'ed to different systems.... one system/SSH reported that the "authenticity of HOSTNAME couldn't be established......." and it asks if I want to continue or something, I didn't and ...