Securing Linux systems and applications; understanding Linux security features.

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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 ...
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4answers
203 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. ...
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2answers
372 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 ...
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2answers
1k 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 ...
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3answers
207 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 ...
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2answers
118 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 ...
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3answers
325 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 ...
2
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3answers
122 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 ...
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0answers
107 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 ...
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5answers
2k 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 ...
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1answer
109 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="" ...
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3answers
136 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 ...
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1answer
212 views

In return to libc how do you know the address of system() in a remote machine?

I have the following scienarion: a vulnerable program running in a server and can be accessed using netcat I have a copy of that program locally and I can exploit it locally using ROP: ./vuln ...
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2answers
217 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 ...
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1answer
65 views

How to validate the confirmation link received when publishing a new PGP key?

I find PGP to be quite a complex subject. I have gotten to a point where I need to give a client a public key for encryption. I have successfully done my homework, generating a public key from my ...
2
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1answer
133 views

Security Features enabled in Linux Debian and Ubuntu

i am actually doing some tutorials about ROP on Linux. So i tried to follow the tutorial and compiled some of the example codes to try ROP in a small scope. But actually when i am trying to exploit ...
4
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1answer
192 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 ...
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2answers
121 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 ...
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2answers
349 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 ...
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3answers
107 views

Is it safe to share my hostname

I am using GNU/Linux. Sometimes, I copy/paste code from the terminal (like user@hostname ..) to put it in a forum thread or a blog ..etc And I was always wondering that it is better to hide it . Is ...
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1answer
54 views

How to fuzz shared objects?

I know there have been similar questions about that topic, but I think mine differs from the others. I have this application which I am able to crash, but the error seems to happen inside of a shared ...
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1answer
253 views

How to detect malicious code sending information to attacker's server in linux

Suppose you have some malicious code on your linux laptop, for example a rootkit or trojan or something like that. Now restrict your attention to the case that the malicious code does transfer some ...
3
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1answer
2k 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 ...
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1answer
141 views

Most secure SSH server [closed]

Which SSH server (compatible with Debian Wheezy) has the fewest (if any) exploitable security bugs?
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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 ...
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1answer
250 views

Linux kernel 3+ system call table modification detection [closed]

Is there any available tool which can check kernel 3+ system call table for modifications? Also I want to know, is there any automated general tool to check Linux for unknown rootkits? Not like ...
1
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1answer
336 views

Booting into Live USB Linux

If I have a Live USB Linux stick and I plug it into a computer which is not connected to the internet and boot the computer using the Live USB stick. How secure is this interms of not leaving any ...
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4answers
325 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 ...
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1answer
751 views

What to do with .hash files when cracking WPA2

So, I'd say I'm one level above n00b. I've gotten to the point where I have accomplished a WPA Handshake (and saved the output as xxx-01.cap). I have also downloaded these hash tables (if that is the ...
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4answers
199 views

One computer with multiple OSs in different drives

I use my personal computer for both programming work and gaming at my free time(and sometimes penetration testing) all these in different operating systems each. The problem is that I dont really ...
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5answers
761 views

Detecting unknown keyloggers

On a Linux system, is it at all possible to detect unknown keyloggers? Keyloggers which are new and haven't made it to any detection software's database?
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2answers
259 views

Secure Way of Encrypting Your Bash Shell Script [duplicate]

How can I encrypt my bash shell script on Linux server The shell script contain credentials of other servers for remote access. The problem is I do not want others with same level of access to view ...
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4answers
371 views

I only use windows for games. Do I need anti virus protection?

I use Linux, and even though I'm not pretending my system is virus-free, it's generally accepted that even an aggressive firewall is not a requirement. I want to install Windows 7 on a machine which ...
0
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1answer
45 views

problem upgrading openssl on ubuntu servers [closed]

I'm running Ubuntu x86_64, and want to upgrade to OpenSSL 1.0.1.f. wget <openssl latest> tar -xzvf openssl.tar.gz cd <openssl dir> ./configure --prefix=/usr make In the console output, ...
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1answer
71 views

Does TRESOR protect against attacks like HeartBleed

I was wondering if the linux TRESOR module (http://en.wikipedia.org/wiki/TRESOR) would protect a webserver against HeartBleed or other similar attacks.
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1answer
45 views

Method/program for editing secure files

I'm not entirely sure if this is on-topic for Security.SE, but it doesn't seem entirely off-topic either, so I'll try. :) I keep a couple of (GPG-)encrypted files with more-or-less sensitive ...
7
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1answer
3k views

Has Linux Mint updated the OpenSSL library for LMDE (Heartbleed bug)? [closed]

Background I am using Linux Mint for one of my servers and have been trying to find out if the Linux Mint Debian Edition(LMDE) has updated their repositories with patches for the OpenSSL bug. I ...
2
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3answers
365 views

Can I use 777 file permissions inside server virtualisation (that only I have access to) without worry?

For this question, please assume I have followed every possible security measure to secure my Linux server. Only I have access to the web server via one open SSH port. If there are security issues ...
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0answers
65 views

Deleting undeletable files on a hacked Linux machine [duplicate]

I've got two Linux machines hacked recently and the hacker/bot has put a lot of stuff in the /root directory. Luckily he did not disable user access, so I was able to login and kill the programs he ...
0
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1answer
239 views

RAM memory data remanence and double boot, risky?

I wonder if my setup can be risky. To give a good starting point for answers I would briefly sketch the situation setup: double boot system GNU/Linux and Microsoft Windows GNU/Linux is on 2 ...
7
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2answers
1k views

Securing Docker and LXC

The concept put forward by Docker and LXC seems to be, from a security perspective, a move in the right direction. Afraid of a MySQL zero-day? Run it in a Docker container and it won't be able to ...
3
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1answer
521 views

Enterprise Anti-virus for Linux?

I know this question is probably at risk of offending the guidelines but our IaaS provider was unable to offer us an anti-virus solution for our Linux servers. We are deployed in an enterprise cloud ...
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2answers
93 views

Hardware-restricted root login

I was thinking about how security on my Linux server can be increased and came up with this question: If most intrusions are performed by gaining remote access to machines, would it be possible and ...
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2answers
88 views

Verifying integrity of text files

While I was away from my home I needed to do some work on a java program so I booted a friends netbook(windows 8) I had with me and finished most of the works I needed to do there. Tho when I returned ...
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2answers
176 views

How do I prove for my client that unused ports are closed and unused services are disabled?

I have seen advice that I need to close all unused ports, and disable any unused services in order to secure my servers. How can I prove, beyond any doubt, to my client that I have done this? I need ...
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1answer
472 views

how to stop people hacking a website build in cakephp with linux host [closed]

I have been wondering how to stop intrusion/hack in a website build in cakephp. The neccessities that I have done so far are updated framework strong password frequent password change removed ...
1
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1answer
143 views

How can I verify my machine is not vulnerable from a specific exploit?

I'm running Ubuntu 8.04 TLS linux 2.6.24-23, I find that CVE-2009-2692 which exploits by using sock_sendpage() null pointer dereference. It describes this exploit affects linux version prior to 2.6.31 ...
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1answer
429 views

Why does the linux XRDP module use a 512 bit RSA key? [closed]

Why does the linux XRDP module use a 512 bit RSA key? 512 bit RSA keys are broken by now. How can this be safe?
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1answer
888 views

How the shopkeepers are getting MAC address of wifi enabled smartphones

It is clear that some big mall's are tracking all the wifi enabled mobile phones before they are connected to the network..how can it been done? I have the similar issue.. how to get the MAC address ...
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1answer
150 views

Linux security books [closed]

I am trying to find an updated book (preferably from 2012-2013) that can cover linux security aspects comprehensively. I searched on Amazon and found that most Linux security books are from back in ...