Securing Linux systems and applications; understanding Linux security features.

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1answer
15 views

How secure is user-mode Linux, in terms of protecting the host system?

Two questions about User-Mode Linux: Suppose that a privilege escalation attack is used to gain root in a UML guest. Assuming modern (3.0 or later) host and guest kernels, is it trivial to escape ...
4
votes
1answer
76 views

Is a Linux environment PCI compliant if the swap file is not encrypted and PANs are loaded into RAM?

Is a Linux environment PCI compliant if the swap partition/file is not encrypted and PANs are loaded into RAM by an application?
7
votes
4answers
103 views

DNS spoofing of linux distribution repositories

Question(s) Is it possible to "redirect" linux-update-repos via DNS spoofing (e.g. DNS cache poisoning) to a malicious website, so that harmful software (updates) will be installed, when running the ...
2
votes
3answers
60 views

VPS Privacy: OpenVZ vs KVM vs Xen

Considering OpenVZ, KVM and Xen: Which VM technology is the most difficult for the host's administrators to access given an encrypted root partition? Can I have a reasonable expectation that rogue ...
0
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2answers
46 views

How exactly does this Flash malware function on Ubuntu?

In this video, an experienced Ubuntu user manages to infect his system with some sort of malware. This is the first example I've ever seen of truly successful malware in the wild aside from privilege ...
0
votes
1answer
37 views

Ubuntu 12.04 server attacked using Wordpress vulnerability (plugin?) [duplicate]

Env Rackspace cloud server Wordpress 3.9.1 Ubuntu 12.04 Linux web.mydomain.com 3.2.0-67-virtual #101-Ubuntu SMP Tue Jul 15 17:58:37 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux History These may ...
1
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1answer
53 views

Running an Open Server (contents are visible)

I'm considering the possibility of running an Open Server, as I would call it, that is, a server where as much of its contents are publicly visible as possible. I would like to give read access to ...
-1
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0answers
20 views

Why isn't auditd logging file deletes? [migrated]

I have auditd installed on 64-bit Ubuntu 12.04 to track down some unexpected deletes (nice discussion of auditd). This is my rule (tagging deletes with the deletes keyword): -a exit,always -F ...
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3answers
126 views

Help me catch someone red handed on our server.

I first tried to log in this morning and our password was changed on our ubuntu server. I contacted our server support and they told me that I had just been fat fingering the password. I thought it ...
0
votes
1answer
53 views

What Linux software can I use to explore entropy of a file?

I've heard of tools that could be used to graph entropy of a file. Is there a graphical Linux program that I could use for this job that would let me conveniently explore which blocks of a file have ...
2
votes
3answers
70 views

Is there any way to block LD_PRELOAD and LD_LIBRARY_PATH on Linux?

Preferably with a vanilla Linux kernel i.e. not using SELinux or GrSecurity? Lately there has been a case of in-the-wild UNIX server malware: ...
2
votes
2answers
88 views

the dangers of internet forums - what is FUD, what is not

I just visited a forum and a member knew what OS I was running without me saying anything (a not TOO common distro of linux). Now I'm not sure how he exactly he might have done it, or what information ...
2
votes
1answer
31 views

What is a secure mechanism for wireless communication between Android and Ubuntu?

I have come across a few Android apps that provide various features for communicating with a desktop machine (sending text or typing in one direction or another, controlling the desktop pointer with ...
24
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4answers
2k views

Should I get an antivirus for Ubuntu?

Considering the recent thread regarding anti-virus for the Mac I wonder how many of the arguments put forth are relevant today to Linux systems, specifically Ubuntu. There are no known Ubuntu ...
0
votes
2answers
46 views

How to hide or obfuscate the type of OS?

I get the OS type of a remote host by: connecting to an open port (telnet <host> 22); using Nmap (nmap -A <host>). What are techniques and how to hide or change the information about ...
1
vote
0answers
15 views

How do I have automatic encrypted backups? [migrated]

I have a jailbroken iPhone, 2 Laptops, and another server. I will set up these devices to backup files to a main backup server I have but I'm wondering how I can have this done automatically while ...
2
votes
1answer
99 views

Is it safe to disable connection tracking in iptables?

While reading about NOTRACK target of raw table in iptables, I encountered an article suggesting that for certain traffic you could (or even should) disable connection tracking. The two examples were: ...
2
votes
2answers
72 views

PHP shellcode inside /tmp. Is the server compromised?

I have a Debian 7 VPS that runs Nginx, PHP5-FPM and MariaDB. This server runs a couple of WordPress installations, phpMyAdmin and Roundcube Webmail. One is my personal blog running WP 3.9.1 and ...
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0answers
18 views

Should my server ever need to directly communicate with the NAT gateway? [migrated]

What I mean by ``directly communicate'' Does it ever need to receive packets with the gateway's IP address as the source IP address, or send packets with the gateway's IP address as the destination ...
0
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4answers
58 views

Can a virus on the host affect the VM guest [duplicate]

let me explain my problem. The wifi on my macbook suddenly stopped working so tried to use my usb wifi adapter on a linux VM. But the funny thing is that nothing works on the guest vm either... Well ...
2
votes
1answer
51 views

Can a malicious user do any harm using /dev/kvm?

I'd like to know if giving access to Intel version of /dev/kvm on Linux to a user that just wants to spawn VMs gives him any extra privileges. That is, are her VMs subject to process scheduling just ...
2
votes
1answer
19 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 ...
0
votes
2answers
102 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 ...
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votes
1answer
47 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 ...
0
votes
2answers
124 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
29 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 ...
4
votes
2answers
142 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?
6
votes
3answers
160 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
59 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
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 ...
3
votes
3answers
104 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
1answer
59 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 ...
0
votes
1answer
39 views

Wireshark: could “Follow TCP Stream” yield an empty window? or is it a bug?

I am capturing a pop3 netcat connection (port 110) using Wireshark, on Debian linux (Kali). After filtering packets with (tcp.port eq 110) I get few packets but once I R.Click on any and click "Follow ...
2
votes
3answers
82 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 ...
1
vote
2answers
81 views

Storing SSH private keys on an Android device

(I'm not sure if this better belongs on unix.se or android.se, but since it's primarily security-related, I'm asking it here) I use my Android device to access servers for quick on-the-go ...
1
vote
0answers
427 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: ...
0
votes
2answers
79 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 ...
0
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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
54 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 ?
6
votes
2answers
141 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
84 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
162 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. ...
2
votes
1answer
123 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 ...
3
votes
2answers
298 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
101 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 ...
2
votes
2answers
108 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 ...
0
votes
3answers
143 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
votes
3answers
112 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 ...
0
votes
0answers
53 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 ...
12
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 ...