Securing Linux systems and applications; understanding Linux security features.

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7
votes
2answers
293 views

Prevent ARP spoofing with dynamic static entry on Linux

ARP spoofing detection/prevention seems to be quite popular here. With other techniques like port stealing aside, I'm wondering if the following could work to prevent it: Whenever my Linux ...
5
votes
1answer
179 views

Automatically enumerate missing patches on penetration test

Nessus, when running a credentialed scan can check patch levels and return vulnerabilities when a package is one that hasn't been updated to the latest, non-vulnerable version. What is a good way of ...
1
vote
1answer
97 views

Strange entry in Apache's ports.conf

I am not sure if this may indicate a compromised server or if I'm just being paranoid. While fiddling around with Apache and Webmin on a new Ubuntu 14.04 virtual server (as well as DNS records for ...
4
votes
3answers
75 views

How risky is to use non-free wireless network driver?

Intel wireless network adapter in my computer requires a non-free driver to work. I don't want to install non-free software to my debian system. However it is a notebook and without wireless network ...
2
votes
0answers
37 views

Is an unprivileged LXC where the host user itself is mapped to 0 less secure of one where one of its subids is mapped to 0, and why?

Instead of creating "common" LXC unprivileged containers where all the users are mapped to (unprivileged) subuid/gid of my host user, I'm considering a mapping where my host user itself will be mapped ...
8
votes
5answers
2k views

I don't recognise my DNS server's address: does this mean I am compromised?

I'm using the Ubuntu GNOME Linux distribution as my desktop. Recently, it became impossible for me to connect to the Internet with it. When I checked its network settings, I saw that the DNS address ...
1
vote
0answers
31 views

iptable ip_conntrack_max testing

I was trying to understand how ip_conntrack_max works so i have created two VM and set ip_conntrack_max to 10000 I used hping to open 10000 udp connection on VM using following command hping --udp ...
1
vote
3answers
499 views

TSource Engine Query DDoS attack

My gaming machine is under DDoS attack and when I used Wireshark I found the following string "TSource Engine Query" in all UDP packets coming from random IP's. I found using Google that some gaming ...
4
votes
3answers
227 views

How to choose a linux for learning? [closed]

I am beginner in Security. My first assignment is about "Linux firewall using IPTABLES" . I know about Ubuntu, backtrack and kali Linux. How to choose a Linux distribution to learn about security?
1
vote
1answer
276 views

Cannot connect using ECDH-RSA-AES256-SHA

I try to establish an SSL connection using the ECDH-RSA-AES256-SHA cipher using OpenSSL, but it fails saying "no shared cipher": On the server, I run: $ openssl s_server -cert selfsigned_cert.pem ...
2
votes
1answer
268 views

Security research on Operating system security measures, where to start?

I am researching on operating system security, And I don't know where to look for more information on this. I could find the following sources, but I need more guidance. Sources: Microkernel ...
5
votes
1answer
175 views

My dlink router seems to be compromised

By chance I read today about this huge vulnerability regarding my router Dlink DIR-600. ( http://www.s3cur1ty.de/m1adv2013-003 ) Just out of curiosity about what I would find, I tried to send some ...
4
votes
2answers
847 views

Malware (adware?) infection on linux

Recently I've get stuck with a malware(adware/virus ?) which I can't remove. here is the condition: I'm using Linux (Archlinux), it's uptodate and I don't install any packages outside standard repos ...
1
vote
1answer
43 views

Sensitive information to exclude from Linux server before providing complete backup to vendor for troubleshooting [closed]

A vendor requested a complete backup of a server for troubleshooting a bare metal restore issue, but they said we are free to exclude any sensitive data. I’m thinking I’ll exclude: /etc/shadow ...
-1
votes
1answer
475 views

SQLMAP --OS-SHELL error [closed]

root@kali:~# sqlmap -u http://www.a***********.com/info.php?id=2 --os-shell _ _ _| |_____ _ {1.0-dev-nongit-20150907} | -| . | | | .'| . | || |||||,| | || |_| ...
8
votes
7answers
330 views

is it possible to keep something invisible to the server admin?

Let's considering the following scenario, an investment firm runs a computer cluster(using red hat as os), some computation which involves some company's trading secret will run on it, there is a SA ...
3
votes
2answers
393 views

Does CVE-2015-5352 work if there is no active X-Server?

My security program shows that one of my servers is vulnerable to CVE-2015-5352. If X-Server is not running (not even installed) is the system really penetrable by that vulnerability?
-4
votes
3answers
102 views

Reverse Engineer and Exploits researching [closed]

Can some one give me a start point for finding exploits in software and reverse engineering? I need some kind of a book or a site... I have background with programming with high and low level such ...
1
vote
2answers
94 views

Public Key Pinning and subdomains

Shortly I have intend to install new webserver and I'd like to secure users a little bit more. I already have domain, (virtual) server and everything else that matters when configuring a server. ...
-2
votes
2answers
257 views

Use of Nmap ssl/http md5 and SHA1 hashes

I have below stated result on of the system by map: 443/tcp open ssl/http Apache httpd 2.0.52 ((CentOS)) | http-methods: GET HEAD POST OPTIONS TRACE | Potentially risky methods: TRACE |_See ...
4
votes
2answers
84 views

Is it a good practice to use certificates as a mean of client identification in a cloud environment

My software system is running a cloud infrastructure where having Linux machines VPN into OpenVPN gateway is a setup requirement. Also, there may be cases when software on the aforementioned Linux ...
5
votes
3answers
5k views

Is Linux spying on its users? [closed]

If you install some kind of Linux distributions on your computer, is their a possibility that their owners may spy on you? For example, can Ubuntu, Kali or Arch linux send data to its owners on what ...
0
votes
0answers
25 views

Get data file off critical database host

Re-wording this question to hopefully be more understandable. Thanks for the feedback. We have a data warehouse which sits in our production environment. Our data engineers can get to the host via ...
6
votes
1answer
433 views

Are encryption keys wiped from RAM before hibernate, or how to do it (Luks and Truecrypt)

Using Linux, I have system and swap/hibernation partitions encrypted with LUKS, and data partitions encrypted with Truecrypt, and I am wondering when I put my laptop to hibernation if the encryption ...
-4
votes
1answer
94 views

Time-based password change [closed]

I have created this script and it runs great, but important questions remain. Is this script useful and secure? Does it have any possible problem or weakness? root@010010:/# ls -la ...
2
votes
1answer
250 views

Can BIOS firmware log keyboard input? If so, is there any way to detect and prevent it?

Recently I purchased a server board made by Lenovo with a "Intel Management Engine" inside BIOS. It is said that it is able to intercept and redirect keyboard input, even if an operating system is ...
3
votes
1answer
90 views

How use snort with local.rules in offline mode?

I'm using SecurityOnion distro and I would to run snort on my pcap files. Is there a way to specify just one rule? I couldn't understand whether local.rules is used. How can I show only the result ...
5
votes
2answers
366 views

How to secure a local socket?

I have made a service written in c that runs on the Android operating system as a core service. I have a few Android apps which communicate with this service via a socket connection (Java -> C). My ...
5
votes
1answer
416 views

What are the mitigating factors for CVE-2015-5364?

CVE-2015-5364 describes a UDP based DoS vulnerability in the Linux kernel that can be used to deny processing cycles to the host operating system and its applications. ...
11
votes
3answers
5k views

Are there ransomware infections of Ubuntu Linux in the wild?

Due to the recent media coverage of ransomware attacks several people for whom I've provided personal computer support in the past have expressed concerned. The majority of these people are running ...
8
votes
2answers
183 views

Why does Android use SELinux?

To restrict/sandbox processes Android uses SELinux. Why was that chosen and not the linux capabilities or cgroups+namespaces solution? After all the cgroups+namespaces is kind of home grown for them ...
0
votes
1answer
237 views

What is a Truecrypt alternative with deniable encryption for linux? [closed]

Preferably an alternative that is Free Liberating Open-Source Software/ FLOSS. I would have used Truecrypt, but it has been discontinued.
2
votes
2answers
221 views

How secure is loging into internet banking via an https library?

My bank does not have an API so I want my server to log in and check incoming payments to notify me if a client has paid or not. I would like the server to log in and scrape using Beautifulsoup and ...
2
votes
1answer
209 views

PPP over SSH - is this correct?

I see a lot of talk online about whipping up a VPN connection using PPP over SSH. This term confuses me, as SSH is an app tier protocol and PPP operates on the data-link layer. So, my question is: ...
108
votes
8answers
15k views

Are there technical differences which make Linux less vulnerable to virus than Windows?

What makes Linux so different than Windows in terms of anti-virus needs? My question is not if I should get an anti-virus for my Linux. I perfectly understand why an AV is important. I would like ...
3
votes
1answer
57 views

Unauthorized file writes on Linux

Suppose my web browser or any other web-connected app has a minor security hole that won't allow an attacker to run code but will allow them to write a piece of text into a text file I own. On a ...
2
votes
0answers
405 views

Is XSP suitable for Internet facing, production hosts? (either self hosted, as an Apache plugin, or FastCGI)

XSP is portable version of ASP.NET that allows for operation on OSX, Linux, and Windows. It's an alternative to IIS, and hosts its own web server, or can plug into existing web servers such as ...
5
votes
1answer
96 views

VirtualBox: Ubuntu With or Without Virtual Hard Drive

I've been working on a setup using VirtualBox that uses the Whonix Gateway as a Tor middlebox and I am planning on using Ubuntu for the workstation. I don't plan on storing any information on the ...
12
votes
1answer
5k views

Diffie Hellman parameters still calculating after 24 hours

I have a fresh install of Arch Linux on a RaspberryPi model B. I'm setting up OpenVPN and using easy-rsa with OpenSSL 1.0.2d to generate initial keys and certificates. All went fine until I ran ...
8
votes
2answers
5k views

Do these regex show that I was hacked?

What do these regex commands mean? I found them when I ran the history command: grep --include=\*.php -rnw . -e "update.creditcard" grep --include=\*.php -rnw . -e "e41e" grep --include=\*.php -rnw . ...
2
votes
0answers
59 views

Can high network usage be detected and prevented in Tor? [closed]

I've already asked this question here but as of yet it has no views/answers. I was wondering if there is any way for Tor to detect high network usage in the context of transferring large files using ...
3
votes
1answer
120 views

Is installing Debian package safe?

If I understand correctly, the maintainer scripts in Debian packages are executed with root privileges. I assume that this means that, contrary to my expectation, installing a malicious package can ...
4
votes
1answer
287 views

Decryption using GRUB and TPM

I'm trying to plan security routine for my new Linux install and few questions came up during searching for solution which meet my needs. Is it possible to use private key from TPM in GRUB to ...
15
votes
8answers
1k views

Is it possible to prevent a file type from being determined in a Linux system?

I have several files on my Ubuntu system, which are LUKS encrypted partitions. For my own shame up to this day I thought that simply changing binary file's extension will be enough to hide what a file ...
1
vote
3answers
107 views

Protecting Uploaded Confidential Files [closed]

We have a web application in Linux (App A) using PHP and Zend and another in Windows using Asp.net C# (App B). They both access the same database. App B is for internal use only while App A can be ...
1
vote
1answer
116 views

Securely hide a directory from the OS using java?

I have a project to do for my master's degree and I need to do a Java app which loads a file (read some attributes and copy the file to a working directory), basically any file, and make the working ...
1
vote
2answers
76 views

Detect SSH InBound / Oubound Connections

I'm noodling with the idea of managing SSH connections on Linux server using a program (not sure what it will be written in yet) that monitors inbound and outbound connections. Is there a way to ...
2
votes
1answer
57 views

Is it possible to use obtained wildcard certificate on more than one server?

We are using two Debian servers in our company (with apache 2 as httpd) and our services are split between those two of them. One server has the website, the other has some minor sites under ...
-4
votes
1answer
3k views

Kali Linux Veil-Evasion install problem [closed]

I can't install Veil-Evasion. I have this error: Installing (Wine) i386 Binaries Reading package lists... Building dependency tree... Reading state information... Package wine-bin:i386 is ...
17
votes
3answers
1k views

ISO27001 and Linux/Ubuntu

My company has an ISO 27001 certification. They provided me a new laptop with Windows 8 OS in it. I asked if I can have a Linux/Ubuntu OS installed, they said that it is not possible due to the ISO ...