Securing Linux systems and applications; understanding Linux security features.

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2
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1answer
26 views

How do I customize /proc permissions?

So that: Only process owners, and root, can access information about their processes, Or, at the very least, cmdline permissions are only readable by root, and My system (CentOS 6.x) still runs ...
5
votes
4answers
1k views

What are the most common files to check with File integrity monitoring software?

I have a file integrity monitoring suite and in it I have to select specific files and folders for it to monitor. There are some obvious services that I want monitored like our web-server. Is there a ...
0
votes
2answers
103 views

Store a file on a harddisk without root having access to it

Is there a way to store a file on a disk as a user so that even the root user has no access to it? I tried EncFS but that is no solution because the root user can switch to every user, so he/she can ...
-1
votes
1answer
53 views

How should privileged accounts be secured in both Linux and Windows?

I have recently started work in application security at a mid-sized firm, having transitioned away from 5+ years in security consulting (pentesting, etc). One of the biggest challenges I see here from ...
10
votes
4answers
2k views

environment variable accessibility in Linux

Perhaps this is a trivial question, but how accessible are environment variables in Linux between different users? e.g. if Alice executes export FAVORITE_FOOD=`cat /home/alice/fav_food.txt` Can ...
0
votes
2answers
168 views

Clarifying MITM attacks and Digital Certificate requirement

We are running a Portal application for our client with Payment Gateway integrated. Payment gateway uses SSL as it is suppose to be . The concern for me is that our Portal application does not use ...
0
votes
1answer
34 views

benefits of xinetd for a web server

What are the pros and cons of using xinetd for a web server running on a VPS. Assume the following measures have already been taken to secure the system: system hardening, latest updates, minimal ...
1
vote
2answers
36 views

How can we know which debian package correct which CVE

We can found on the debian's website CPE/Aliases List, CVE List related to packages. But I can't figure out where can we know which patch of packages correct which vulnerabilities ? For instance : ...
4
votes
2answers
149 views

You've just acquired a newly created CentOS server, what should you do to secure it?

I've just acquired a new CentOS server, which will be hosting a Ruby on rails application, it is public facing. What should I do to secure this server?
-2
votes
1answer
64 views

Proccess to exploit an OS vulnerability [closed]

What are the steps to use an exploit on an OS vulnerability? I tried the popular ms08-067 on an XP machine, following a guide found on the internet, discovering Metasploit etc., but I can't figure ...
15
votes
7answers
1k views

Defence Against Keyboard Keylogger

I am wondering whether there is a way to defend against USB Keyboard Keylogger (obviously other than physically checking the keyboard every time after leaving my computer unattended). These days, ...
5
votes
3answers
257 views

How to sandbox Iceweasel (Firefox) on Debian? [closed]

Are there any tools for sandboxing Iceweasel (Firefox) on Debian systems? I'm mostly interested in tools distributed by Debian. (An equally trustworthy source would be second best.) (I suppose that ...
1
vote
2answers
66 views

What's there to harden for a home Unix-box behind Comcast cable modem?

I'm learning that much of the security advice I come across under the "hardening" heading simply does not apply to a single-user home desktop box sitting in a private wireless IPv4 LAN behind a ...
2
votes
2answers
231 views

I've found security vulnerability in current linux distribution. What next?

I've installed ubuntu server 12.04 on VM two weeks ago. I've created regular snapshots. XXX time ago I've noticed unusual activity and I've found that a backdoor was installed into my server. One of ...
47
votes
7answers
5k views

Can “cat-ing” a file be a potential security risk?

I often use cat on the console to view the contents of files, and every now and then I accidentally cat a binary file which basically produces gibberish and system beeps. However today I've ...
3
votes
3answers
113 views

Protect partition from formatting

How can i protect my Linux and Windows partitions from being wiped,from a windows installation CD,with password?
2
votes
2answers
30 views

Is there a website or other resource that lists operating systems/platforms and the included root certificates?

I need to choose a certification authority (CA), to get a certificate, but I noticed that there are several of these only present in some operating systems/platforms like windows. I need to choose one ...
1
vote
2answers
114 views

Open Source OS - code you see vs code you get

In this question I will use the example of Linux OS, but I am also interested in general situation. Linux OS distributions are famous for being open source and thus rather secure. But how can you be ...
2
votes
3answers
92 views

How to setup a dedicated home machine (Linux) for secure transactions?

I would like to set up a computer at home (preferably running Debian, or some other flavor of Linux) to be used only for secure financial transactions. The idea is that, by strictly limiting what is ...
3
votes
2answers
171 views

How do shared hosts protect different sites?

I host all my websites from a single VPN, and am about to sell some limited space of my Linode to a friend to host their new blog. It'll simply be another entry in Apache, and then a dedicated folder ...
11
votes
4answers
2k views

How secure is NOPASSWD in passwordless sudo mode?

On all our boxes we have ssh access via keys. All keys are password protected. At this moment the sudo mode is not passwordless. Because the number of VMs are growing in our setup, we investigate the ...
1
vote
5answers
1k views

Encrypt-function inside PHP code that you have to publish

If you write a PHP application, where you have to deliver the compiled code to the customer, how could you include a functionality to send encrypted data from that application to others, and include ...
1
vote
3answers
581 views

What is the most secure way to set up web server user permissions? [closed]

The default Debian way of setting up a common web server (Nginx) is to run the main process as root and unprivileged workers as www-data. In order to allow for the worker processes to read/execute web ...
1
vote
0answers
455 views

GnuTLS ServerHello exploit (CVE-2014-3466) - how to verify?

So pretty much all of the GNUTLS world is worrying about CVE-2014-3466. I checked my Kali and it responds with this - # apt-cache rdepends libgnutls26 | grep -v lib Reverse Depends: ...
3
votes
4answers
194 views

Find out what Linux software is trying to phone home

I have seen some suspicious outbound communications blocked on my VPS, which hosts a small experimental Web site, and want to find out which application is making the attempt. The server is running ...
69
votes
3answers
9k views

Is a rand from /dev/urandom secure for a login key?

Lets say I want to create a cookie for a user. Would simply generating a 1024 bit string by using /dev/urandom, and checking if it already exists (looping until I get a unique one) suffice? Or should ...
0
votes
2answers
81 views

Encryption in Linux: covenience and security [closed]

I was using TrueCrypt until recently, until one of two options has happened: either it was discontinued or its web-site truecrypt.org was hacked. Any option implies that I don't trust it anymore. So ...
2
votes
1answer
140 views

Using a TPM with Linux

I have the need for a company laptop (Dell e6540) that contains our java application on it to go out for evaluation purposes. For this reason I would like to make sure that the HDD is protected from ...
0
votes
0answers
54 views

My server has been brute forced what now? [duplicate]

I have installed a raspberry pi for fun at home. I opened the port 22 and this morning I was concerned about someone brute forcing my server. I ran this query : cd /var/log;zgrep ssh auth*|grep ...
0
votes
1answer
60 views

How to secure an embedded linux image

I'm building an image with openwrt sdk and i want to secure my image (by encrypting filesystem for example).. How can i do that to prevent anyone from seeing my sscripts or programs running ?
13
votes
5answers
1k views

Hackable linux distributions

A few years ago we had that awesome Linux distribution called Damn Vulnerable Linux. But unfortunately it looks like the project is dead. So my question is are there other Linux distributions which ...
6
votes
2answers
154 views

How often is ASLR randomness refreshed, in Linux?

Most Linux distributions now use ASLR for many programs, to randomize the layout of memory. How often is the randomness used for this changed? If I re-run the same program multiple times, will it ...
0
votes
1answer
87 views

VPN tunnel in VPN tunnel

I'm wondering if there is an easy way to establish VPN tunnels through other VPN tunnels to get onion routing like properties (sender anonymity). Since VPN builds a tunnel, it should be easy to set up ...
1
vote
4answers
174 views

How to detect credit cards harvested from memory?

Had a chat recently with PCI compliance specialist and got to realize there is a way to steal raw data from Apache / Nginx memory e.g. credit cards. It's called "harvesting" and becomes pretty common. ...
6
votes
7answers
5k views

Physical computer security, how to disable USB ports when the computer is 'locked'?

Lets say my PC & server is in an environment where a theoretical attacker has physical access to the machine while I'm not there. Now the data is encrypted on the hard drive with TrueCrypt. ...
6
votes
4answers
1k views

Security of the KWallet password encrypting application?

According to http://gaganpreet.in/blog/2013/07/24/kwallet-security-analysis/ , the KWallet password management system is quite weak, it uses key splitting, Blowfish 56, and no salt. The key ...
0
votes
3answers
161 views

How to secure ubuntu desktop after a hack? [closed]

I have two ubuntu laptops that were recently compromised. I understand that it's probably a fruitless endeavor to try to find the hacker. I want to know how to secure my ubuntu desktop so that the ...
4
votes
2answers
434 views

How to pass PCI DSS 2.0 anti-virus requirement (5.1) on Linux?

PCI DSS 2.0 Requirement 5.1 states: 5.1 Deploy anti-virus software on all systems commonly affected by malicious software (particularly personal computers and servers). This requirement ...
0
votes
3answers
115 views

How to set iptables to drop packets that I'm not listening on?

I've got a Kali Linux box I use for pen testing. I would like to configure my machine to DROP incoming packets, but only when I'm not listening on them. e.g. if I run a netcat listener on port 80, I ...
3
votes
2answers
112 views

security via chsh

I am developing a program that I want people to be able to connect to and use via ssh. I've decided a simple way of doing this would be to create an account for them on my linux server, and change ...
3
votes
1answer
672 views

Best method to sandbox X applications in ubuntu

What's the best way to sandbox an X application like firefox or thunderbird in ubuntu (going into the direction of what qubes os does, but only for single applications)? I know there are many ...
2
votes
3answers
115 views

Securing data on a server

I have a server which has 'loose' physical security (somewhat easy for the entire server to get stolen). For the sake of the question, let's assume that anyone can access the server physically, what ...
2
votes
3answers
324 views

Encrypting Backups on Linux

I'm working on an automated backup solution to protect my files on my Linux servers. However, I'm not sure about how to securely encrypt the resulting archives. I am using 64bit linux, and I am ...
0
votes
0answers
61 views

How should I configure my Tor-dedicated firewall for optimum security?

I'm setting up a Tor-based isolating proxy using the 'Anonymizing Middlebox' iptables rules specified here: https://trac.torproject.org/projects/tor/wiki/doc/TransparentProxy i.e. iptables -t nat ...
16
votes
7answers
4k views

Any comprehensive solutions for binary code protection and anti-reverse-engineering? [closed]

Does anyone know of good products with comprehensive binary hardening and anti-reverse-engineering features? Or better, has anyone seen an independent review comparing products that perform these ...
1
vote
3answers
344 views

Best practice for accessing management port of firewall

I'm in the process of setting up a bunch of servers at the other end of the world (well, 8 hours travel time) in a co-location place. The servers and firewall all have a remote management port (KVM, ...
1
vote
3answers
106 views

How bad is it to *not* reboot a server after kernel updates?

I’m administrating a few Debian Linux server, and install package updates when apticron notifies me of them. Occasionally I see updates to linux-image-[something] packages, but don’t bother to reboot ...
2
votes
1answer
93 views

Analyzing a suspicious email

Today I received a very suspicious email on my gmail account. When I analyzed the content of the message, this is what essentially made up the message. <center> <a alt="" ...
0
votes
2answers
84 views

Ubuntu LVM LUKS Encryption

I've been reading about Ubuntu LVM Encryption, and I understand that it supports the use of Linux Unified Key Setup (LUKS) during installation, which is a block level encryption that encrypts the ...
4
votes
1answer
120 views

Does Linux kernel use DEP for kernel memory?

Does the Linux kernel use DEP internally for its kernel memory? In other words, does the Linux kernel take care to ensure that, when the kernel is executing (in kernel mode), every executable ...