Securing Linux systems and applications; understanding Linux security features.

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2answers
183 views

PCI Compliance Distibution

I run a small e-commerce website hosted on a dedicated server with Debian 6 Squeeze. I need to become PCI compliant (the card industry standard for security). Therefore I have registered with ...
2
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1answer
183 views

Evil maids in the server room [closed]

I am well aware of the fact that physical insecurity in principle means no security. But let´s say I own a root server with full disk encryption which is unlocked/booted via dropbear ssh. In which ...
0
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3answers
999 views

What is the hack attempt going on when I see: did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA

When I look at my sendmail logs, by far the most common "error" I see is the following: Nov 22 16:49:50 MyHostname sendmail[18832]: rAMMnj2u018832: [IP address redacted to hide the guilty] did not ...
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votes
2answers
19k views

backtrack or kali linux ??? Which is best for a beginner pen tester ? [closed]

I am using backtrack right now but i also wish to switch to kali linux if its more interactive. Because i am just a beginner pen tester. I tried with both bt4 and bt5, but novice in kali linux.
8
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4answers
2k views

How secure is NOPASSWD in passwordless sudo mode?

On all our boxes we have ssh access via keys. All keys are password protected. At this moment the sudo mode is not passwordless. Because the number of VMs are growing in our setup, we investigate the ...
0
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1answer
103 views

Strange Virus Infecting My Server

I am currently working on a Web App on my dedicated server (LAMP) and it seems like it might be infected with some strange malware/virus of some kind. When I access some domains on that server (every ...
2
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3answers
1k views

How Tor, Privoxy, Vidalia and Polipo are getting together?

I realized that these applications are frequently used together. What is the role of each software in the mission of anonymity and privacy on the web? While I understand Vidalia is a GUI provider, I ...
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0answers
95 views

What are some good design practices for cross-platform certificate storage?

Question from the Bouncy Castle development list: At present we use the Windows certificate store as: var store = new X509Store(StoreName.My, StoreLocation.LocalMachine); ...
3
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2answers
277 views

Disable local/KVM access on a Linux VPS (allow only SSH)

Friends of mine have previously had issues with VPS security. The security was no fault of the operating system/services themselves, but mainly due to the "Control Panel" that gets forced upon you ...
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5answers
4k views

Can I use Kali Linux when I learn Backtrack well?

I'm new to security issues and I'm almost buying a course at ELearningSec(begginners course,of course), I will in a company and want to learn about offensive and defensive skills to improve the ...
0
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1answer
176 views

Fishy: VMware sends all traffic through akamai

I'm running Linux inside of VMware on the Mac, and on Linux I'm running a program that has connections open to perhaps 4 different machines. On the OS/X side however VMware has only 1 active network ...
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1answer
336 views

Exploit Compilation Problem [closed]

I am trying to compile the following exploit: http://www.exploit-db.com/exploits/10613/ But get the following error: local.c:12:22: fatal error: asm/page.h: No such file or directory compilation ...
7
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2answers
185 views

What output can a program, when executed from a command line, output to generate behavior that is a vulnerability on the terminal emulator?

Reading this post, titled "Fixing Unix/Linux/POSIX filenames", I came across a VERY interesting phrase by the author, which says: Oh, and don’t display filenames. Filenames could contain control ...
6
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4answers
566 views

Security of different OS

At my work we are given a computer to set up at home so if we ever feel like working from home we can do so. The thing is that whenever it comes to developing for java I always prefer using windows or ...
0
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2answers
334 views

Disabling SMEP on x86_64

I have recently been doing some research into kernel exploitation on X86_64. A problem I have run into is that I have found Intel's SMEP to be killing my contrived example of a kernel NULL pointer ...
42
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5answers
3k views

What does Mark Shuttleworth mean by “we have root”?

In a blog post in response to the Amazon privacy controversy, Mark Shuttleworth wrote: Don’t trust us? Erm, we have root. You do trust us with your data already. You trust us not to screw up on ...
4
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3answers
156 views

How can you know what is distributed with your Linux

I'm curious, in theory, how can one know if for example kernel that is distributed with Ubuntu Linux is really what is on https://github.com/torvalds/linux and not some modified kernel which contains ...
15
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7answers
983 views

Defence Against Keyboard Keylogger

I am wondering whether there is a way to defend against USB Keyboard Keylogger (obviously other than physically checking the keyboard every time after leaving my computer unattended). These days, ...
0
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1answer
456 views

Stack Guard vs Stack Shield

I would like to know why nowadays Stack Guard is used everywhere (example: ProPolice in GCC, /GS in Visual Studio), instead of Stack Shield. Both the approaches (i.e. Stack Guard & Stack Shield) ...
6
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4answers
959 views

Security of the KWallet password encrypting application?

According to http://gaganpreet.in/blog/2013/07/24/kwallet-security-analysis/ , the KWallet password management system is quite weak, it uses key splitting, Blowfish 56, and no salt. The key ...
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2answers
144 views

Linux: Blocking outside attempts at attacking computer

in the past when I wanted to block outsiders from attempting to start connections with my Linux machine's various TCP services, what I was told to do was to add this line to /etc/hosts.deny: ...
0
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2answers
259 views

Isolating host machine from external network

How to prevent a host machine from sending/receiving packets with the following network configuration: eth0 - physical NIC :: not configured; tun0 - virtual NIC for VM which role is the gateway for ...
1
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3answers
574 views

What is the most secure way to set up web server user permissions? [closed]

The default Debian way of setting up a common web server (Nginx) is to run the main process as root and unprivileged workers as www-data. In order to allow for the worker processes to read/execute web ...
2
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3answers
316 views

Is there an internal equivalent to fail2ban?

fail2ban is a protection against brute-force that locks a user out after a definable maximum failed login-attempts. But if a user already has access to a server with another username already fail2ban ...
5
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2answers
2k views

Best way to allow sudo access when using ssh keys

Probably a simple question, but I can't seem to find any actual best practices out there. I manage a handful of servers and I am really getting sick of tracking my passwords in pwsafe. I've been ...
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0answers
142 views

Tools to perform benchmark of block/stream ciphers on Linux? [closed]

I would like to perform some benchmarking of different block and stream ciphers for general data (lossless and lossy data) encryption and decryption (with focus on power consumption). To get general ...
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1answer
542 views

Afraid about SSH on my Linux system

I've checked my Linux server (Centos 6) with rkhunter. I found the following in rkhunter log [14:38:54] Checking if SSH protocol v1 is allowed [ Warning ] [14:38:54] Warning: The SSH ...
1
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1answer
216 views

SSH authorized_keys

Can you correct me on this. I create a keypair on my PC. Copy the public key (append to authorized_keys) on the server. Disable password auth on the server, and SSH to server from my PC. I have ...
1
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1answer
77 views

Securing WebHosting Shell Access

If I provide SSH access to users who has paid webhosting service, what security measures should be applied ? What I can think of: SSH keys RSA of 4096 size (shall be secure for a while) Apache ...
5
votes
1answer
109 views

How is using acces() opening a security hole?

The man page for access(2) tells : Warning: Using access() to check if a user is authorized to, for example, open a file before actually doing so using open(2) creates a security hole, because the ...
2
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3answers
2k views

Alternative to AirPcap for Linux?

I need to sniff WiFi packets, but according to AirPcap FAQ page, it just supports Microsoft Windows, not other platforms. Does any alternative of this product work in Linux? Please don't offer Alfa ...
3
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2answers
794 views

Alternatives to SELinux and AppArmor?

With SELinux developed by NSA and AppArmor by Novell [*], what alternate solutions exists when trying to lock down a system and running applications, based on ACL and similar concepts like Zones on ...
2
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2answers
323 views

Apparmor system-wide security — white-listing

I want to only white-list applications that can run on my system using Apparmor, I know it is used to confine applications/programs based on their path names, but what I need is to contain those ...
5
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2answers
4k views

How trustworthy is SELinux? [closed]

Given the ongoing leaks concerning mass surveillance and the fact that the NSA is the original developer of SELinux, I'm wondering whether that means that backdoors should be expected in there? As ...
1
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2answers
422 views

MAC spoofing preventing connection

I'm attempting MAC spoofing on a network I own. I'm connecting to a NETGEAR WNDR4300 wireless router from an Ubuntu Linux machine. The network uses WPA2-PSK [AES] security. Connecting to the network ...
0
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1answer
233 views

How could `iptables -F` lock me out of the server? [closed]

I was just configuring IPtables and whilst doing so, had the default chain policies set to ACCEPT, but when happy with the generated rules I changed that to DROP for all chains. I did not run ...
6
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2answers
310 views

Is there any Linux distro or kernel patch that wipes a process memory space after the process exits?

An application runs on an embedded battery-powered PC, accessible to some restricted public, that stores secrets in RAM. To prevent cold boot attacks and that the PC is stolen to extract its secrets, ...
11
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2answers
982 views

RdRand from /dev/random

"Linus Torvalds, in response to a petition on Change.org to remove RdRand from /dev/random, has lambasted the petitioner by called him ignorant for not understanding the code in Linux Kernel. ...
6
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2answers
673 views

Can i compare linux user permissions without root access?

I've compromised two Linux user accounts on a RHEL machine (neither of which have root permissions) and I want to determine which account is more 'useful' to me in terms of access and privileges. Is ...
0
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3answers
813 views

How to find vulnerable sites on a web server

A client of mine has a managed VPS with dozens of websites on it, maybe even hundreds. Now his server keeps getting infected on a regular basis. The webhost / server admins keep digging in the dark. ...
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1answer
221 views

If someone downloaded 600GB , can that be ddos attack [duplicate]

Last night some one exploit some vulnerability in my site and then upload php script in my images folder . I have the Amazon EC2 server with centos. Now the Hacker downloaded 600GB and increased my ...
0
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1answer
857 views

Using Volatility Framework with Linux memory dumps

I am using Volatility Framework 2.2 to anlayze a Linux memory dump. This memory dump was taken from an Ubuntu 12.04 LTS x86_64 machine with the kernel version 3.5.0-23 I have the profile for it and ...
14
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3answers
759 views

Why doesn't Linux randomize the address of the executable code segment?

I've recently been learning about how ASLR (address space randomization) works on Linux. At least on Fedora and Red Hat Enterprise Linux, there are two kinds of executable programs: Position ...
1
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1answer
281 views

How to authenticate to racoon with a certificate chain if only the root CA is known

I'm trying to setup IPsec using x509 certificates on Linux. I'm using racoon for that task. I've come to the point where the authentication works fine if I keep every link of the certificate chain on ...
5
votes
4answers
277 views

Is Encrpyting Home Sufficient?

I currently have a fully encrypted Windows System, and I'm looking at switching to Ubuntu. Is encrypting my home directory (with ecryptfs) sufficient? On windows this would be problematic due to ...
0
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1answer
243 views

Would adding root to a group open a security hole?

I have a server for which I have created a cron job "sendalerts" to users. Mind you this "sendalerts.php" should be runnable from two methods (via browser and also via a cron job) So cron's job is to ...
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2answers
8k views

Why do some people think Linux is more secure than Windows? [duplicate]

I have no idea if Linux is more secure than windows. I think Linux is more secure but I want to know what is going at kernel level. Somebody told me that Linux have only one main kernel and has it ...
9
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2answers
1k views

Java SecureRandom doesn't block? How?

I know from experience that reading from /dev/random blocks when the Linux kernel entropy pool runs out of entropy. Also, I've seen many articles and blog entries stating that when running on Linux, ...
2
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0answers
87 views

Shorewall stopped policies - routeback

Here goes a very specific question about the insides of Shorewall and Iptables in general. Shorewall supports configuration of "Stopped Policies" using the file routestopped, which defines the ...
0
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3answers
1k views

Security checklist for hosting a website on dedicated server - Linux [closed]

I have been searching for a while now. But i can't find a start-up and advanced sought-of checklist to understand the most important things to consider while going for dedicated hosting server for a ...