Securing Linux systems and applications; understanding Linux security features.

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1answer
27 views

updatedb and encrypted home folders: Does it store unencrypted file and folder names somewhere?

When you encrypt your home folder in Ubuntu and Debian, it protects not only the file contents but also the file and folder names. Yet I see that updatedb and locate works in Debian. When I run ...
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1answer
46 views

How do I secure X server against spyware in a GUI application?

Suppose you have a GUI application, that potentionally may be too curious about your environment, such as the list of window titles. How do I limit application's ability to enumerate windows, capture ...
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1answer
112 views

RHEL 6: PHP 5.3.3 - Is it inherently insecure?

I am talking about the PHP 5.3.3 package that is available in the Red Hat Enterprise Linux repository, running on Apache. From what I can see, as of RHEL 6, it is the latest version (no updates ...
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1answer
67 views

Which hardening methods are used in large linux desktops environments (i.e. Goobuntu)? [closed]

Im courious to know about how these large enterprises secure their linux desktop as Google does with ubuntu LTS. I am the only user at home with linux on the desktop and had already created some ...
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1answer
38 views

Limiting account access based upon NIC used to connect on Linux

I have a server which has multiple NICs (ignoring redundant pairs): 'inward' facing production (connects to other servers); 'outward' external facing production (connects out to the internet via a ...
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1answer
62 views

Linux file information leakage

What information is kept in a linux file about the user and/or system that created it? I want to make some files publicly available, posted on another server such as GitHub or FTP, but I'd rather the ...
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2answers
99 views

Why was LibreSSL PRNG unsafe on Linux?

From the source: https://www.agwa.name/blog/post/libressls_prng_is_unsafe_on_linux The first version of LibreSSL portable, 2.0.0, was released a few days ago (followed soon after by 2.0.1). Despite ...
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3answers
138 views

Is it possible to USB whitelist in Linux?

After watching Black Hat's presentation on the fundamental problems with USB "security", I'm wondering if there's a way to do USB whitelisting in Linux. Is there currently a mechanism that will allow ...
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3answers
78 views

Permissions security scenarios for a web server

Having /var/www/site.com owned by www-data:www-data with a 750 permission for directories and 640 for files, and having my user alexb added to www-data group, I found my self with permission issues ...
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3answers
114 views

How do I ensure that my Ubuntu download has not been tampered with?

I am downloading Ubuntu Linux, and would like to make sure that my download has not been tampered with. Ubuntu has a GPG key, which I could use to make sure that the download is valid -- but how do I ...
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3answers
129 views

Is MS Windows more secure than Linux on this aspect?

The administrator account can be renamed which means the hacker needs to figure out two pieces of information : the user name and the password while there is always one root account in Linux named ...
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1answer
39 views

Throttle network based on OS [closed]

What do I need to learn/know to throttle a clients network based on his/her operating system. For example: Someone in my network using Kali Linux... I would like to throttle their traffic to ...
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2answers
73 views

Is it safe to create live usb on an infected system?

I am using Ubuntu 13.10. If my laptop is infected with malware, can I get rid of it by creating a live usb on it and using that live usb format and re-install the ubuntu ? I mean is it possible that ...
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2answers
99 views

Does the EICAR test work on Linux based antivirus scanners?

Does the EICAR antivirus test work on antivirus scanners for Linux? The EICAR test is described in more detail here: http://en.wikipedia.org/wiki/EICAR_test_file The reason I ask is that it requests ...
27
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6answers
4k views

Is Linux really that secure, with only root password denying external access?

While I was searching online for information about Linux security, the most typical explanation was: Linux is secure, because the root password is required to access the kernel and install new ...
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4answers
5k views

How to prevent BadUSB attacks on linux desktop

What can I do to protect my linux laptop from BadUSB attacks as described here? Perhaps writing an appropriate apparmor profile would help?
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3answers
2k views

Is it better to use a root password, or use 'sudo bash'?

When I am doing a lot of sudo operations, I like to spawn a bash shell from sudo to make the operations go quicker. I am against assigning a root password because I do not like the root account ...
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1answer
59 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 ...
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1answer
108 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?
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4answers
184 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 ...
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3answers
600 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
78 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 ...
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1answer
136 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
58 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 ...
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3answers
133 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 ...
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1answer
71 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 ...
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3answers
197 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: ...
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2answers
109 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 ...
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1answer
73 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 ...
27
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4answers
3k 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 ...
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2answers
83 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 ...
2
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1answer
709 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: ...
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2answers
155 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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4answers
85 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
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1answer
59 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
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1answer
33 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 ...
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2answers
115 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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1answer
63 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 ...
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2answers
181 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
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1answer
81 views

SElinux security context public_content_t for vsftpd

My understanding of SElinux context public_content_t is as public_content_t is required for files shared via a FTP server unless associated with a user home directory Here is my question Does user ...
0
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1answer
49 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 ...
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2answers
160 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?
5
votes
3answers
605 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 ...
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2answers
138 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
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2answers
34 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
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3answers
146 views

Protect partition from formatting

How can i protect my Linux and Windows partitions from being wiped,from a windows installation CD,with password?
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1answer
81 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
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1answer
82 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 ...
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3answers
105 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 ...
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2answers
192 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 ...