The operating system is the software component that provides abstraction of physical hardware, and provides a generalized model for application software to execute without the need for specific hardware knowledge. Questions on the topic of operating system security should use this tag; you may also ...

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271
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13answers
54k views

Are passwords stored in memory safe?

I just realized that, in any language, when you save a password in a variable, it is stored as plain text in the memory. I think the OS does its job and forbids processes from accessing each other's ...
85
votes
13answers
8k views

Why do we lock our computers?

It's common knowledge that if somebody has physical access to your machine they can do whatever they want with it1. So why do we always lock our computers? If somebody has physical access to my ...
61
votes
9answers
10k views

Hardening Linux Server

We have already had questions on here about Hardening Apache, Hardening PHP and Securing SSH. To continue this trend I am interested in what steps people take to harden Linux servers. As in what ...
47
votes
8answers
7k views

Risks of giving developers admin rights to their own PCs

I need to convince my internal IT department to give my new team of developers admin rights to our own PCs. They seem to think this will create some security risk to the network. Can anyone explain ...
42
votes
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 ...
28
votes
6answers
3k views

Secure Linux Desktop

I'm looking for hints about secure linux desktops. Securing servers is no problem. Most recent Software Updates, run only the services required etc. But what about desktops? I'm thinking about details ...
27
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1answer
6k views

iOS Encryption Details

Following on from this question Does anyone have any details/resources on the technical specifics of how apple implement encryption on their iOS 4.x series devices? The Apple marketing material here, ...
22
votes
10answers
3k views

Vulnerable OS's?

Which vulnerable OS's like for example DVL would you recommend for someone to use for the purpose of pentest/exploitation learning?
19
votes
3answers
15k views

How does the Windows “Secure Desktop” mode work?

Can anyone explain (or provide a link to a simple explanation) of what the Windows "Secure Desktop" mode is and how it works? I just heard about it in the KeePass documentation (KeePass - Enter ...
18
votes
1answer
600 views

Is it secure to connect to a remote Windows Server using Remote Desktop only?

I have a Windows Server that I login to from my home. I only use the pre-installed Remote Desktop. Is this a secure way to remote login or should I improve it in some way? If I should improve it, ...
17
votes
3answers
2k views

Are passwords in memory?

I have an encrypted HDD (dm_crypt). That's why I store my passwords in a simple text file. I usually copy/paste the passwords from it. Ok! Q: If I open this text file then it goes into the memory. So ...
17
votes
4answers
3k views

Windows hardening

Can anyone point me at some good resources on Windows hardening? From 2003 upwards.
16
votes
6answers
3k views

How can I protect my computer from my potentially malicious colleagues?

So, I work in this small company (10 people) where we do stuff in programming, for various platforms. I started recently working there (2 months) right after I graduated. My work is not exactly ...
16
votes
8answers
763 views

Should the requirement of admin privileges be extended?

Seeing this comic from xkcd.com made me thinking: Is extending the requirement of admin privileges to things such as connecting to the internet, running the web browser, reading browser and other ...
16
votes
3answers
998 views

Multi factor authentication on Ubuntu workstations, where to start?

Is it possible to have Ubuntu users log in with multi-factor authentication? I was thinking of a combination of pass(word|code) and smartcard (with screen locks when for example smart-card is removed) ...
16
votes
1answer
4k views

Mac OS X from an IT Security Practitioners' Perspective?

What does the Mac OS X offer that it has been recently attracting users with IT security focus? There are sites that specifically focus on "hacking" with OSX, such as machacking.net. Defcon has an ...
16
votes
2answers
2k views

How secure is Keychain on OS X?

Keychain is a built-in app on OS X that stores all of the user credentials, and allows for one to keep encrypted notes in an easily accessible way. Does anyone know how secure Keychain is? I know ...
15
votes
5answers
4k views

Why does the government/military not use special operating systems?

Why does military and government not use special operating systems? I mean, if they do not use generic operating system based on Windows, Linux and Mac and create their own operating system, they will ...
15
votes
3answers
1k views

Can Windows malware harm a Linux computer when it's executed with Wine?

I am an (Ubuntu) Linux user. Sometimes, I have to use Wine for running Windows executables. I would like to know if Windows malware (virus, trojan, worm,...), i.e. malware that was not intended to ...
13
votes
4answers
371 views

Stop software updates after the system is “stable”?

Yesterday morning I had an OS class and we just started the part about OS security. When the professor was explaining what is a patch manager, he told us that a computer company he knows which deals ...
13
votes
5answers
554 views

What is the potential impact of the alleged OpenBSD IPSEC attack?

Recently there is a bit of concern over encryption back doors in IPsec and while the status of this has not been confirmed, I don't know what impact something like this might have. For instance, does ...
13
votes
1answer
738 views

Are there Linux rootkits circulating that directly modify the kernel (without modules)?

It has been said, over and over, that disabling dynamic kernel module loading on Linux increases security. I understand why people give this advice, but I've always assumed that a bad guy could ...
12
votes
5answers
7k views

Linux command logging?

Recently someone broke into one of our linux servers as a non root user. An excerpt from .bash_history: [...] perl perl set +o history set +o history set +o history passwd sdfsdf passwd exit I ...
12
votes
3answers
6k views

Prevent acccess to the C drive on Windows systems

Is it possible to prevent regular users from accessing the C drive via Windows Explorer? they should be allowed to execute certain programs. This is to ensure that employees cannot steal or copy out ...
11
votes
7answers
1k views

Can hackers detect my operating system?

I've seen people demonstrating the use of backtrack to attack VMs. In one of the components of backtrack, it shows the operating system of the targets. Since support for Windows XP is ending soon, i ...
11
votes
7answers
2k views

Can viruses actually inject their code in other processes?

Can a virus really inject its own code into a process so it stays on your computer permantly? The only way to actually remove it is to reinstall your OS. My question is how can it do that without ...
11
votes
4answers
980 views

Are exploits platform dependent?

Looking over an overview of the newest published IE exploit, I noticed what I think is assembly. I don't know anything about exploit development, but I know a little about assembly. Seeing that ...
11
votes
3answers
451 views

Given SSH access, what should I do to protect a server and monitor (dangerous) user actions?

Context: Small business, mostly a software house for web applications but also some desktop software. Many external collaborators, so a variety of outside users with access to the servers. Single ...
11
votes
3answers
462 views

What security requirements do you have for Domain Administrators?

With regard to managing a Windows network, what security polices and processes do you use? For example Do you require/support Smart Card Authentication? Restrict logins from a particular ...
10
votes
3answers
1k views

Attacks against windows kiosk software

I am interested in potential/actual attacks against kiosk software. I am not talking about physical access, or specifically designed kiosk operating systems or shells, bur rather software that runs ...
10
votes
4answers
5k views

OS with encrypted RAM?

Are there any applications, JIT frameworks or operating systems that focus on encrypted virtual memory, or perhaps virtual machines that do something similar? I know there are processors (albeit old, ...
10
votes
6answers
9k views

Is my computer at risk of being hacked when using public Wi-Fi?

I'm sitting at a cafe, using their public Wi-Fi. I don't go on sensitive sites; I basically go to a music site and listen to a live stream, for which there's no login. I don't check my email or visit ...
9
votes
2answers
3k views

Recommend Keylogger for Ubuntu?

I purchased a new laptop recently, and I'm working on hardening it. Specifically, I'm interested in increasing my chances of recovering the machine in the event that it's ever stolen. The system ...
9
votes
3answers
6k views

Security of passwords remembered by Windows

Does Windows XP or Windows 7 encrypt saved passwords? I'm assuming that the user uses local password to logon. The user then uses his own computer to connect to server in work and sets the "remember ...
9
votes
1answer
262 views

What shell binary should I use for the root account on a Linux system?

Is there a security advantage to using a different shell for the root account, either a hardened shell program, or simply a shell binary stored in a non-standard location?
9
votes
2answers
150 views

Does Centralisation Decrease the Probability but Increase the Damage of Exploits?

This question is, perhaps, a tad too abstract for a Q&A site. But it's been playing on my mind for a while, so I'm throwing it out there. Modern systems seem to be increasingly centralised. An ...
8
votes
7answers
1k views

Is there any asymmetrically encrypted file system?

Is there a file system providing a directory where everybody can write, but only the directory owner can read the files? In theory it could be done by encrypting using the public key while writing, ...
8
votes
3answers
2k views

Am I protected from USB autorun malware on Windows 7?

As far as I know, the autorun.inf problem (the possibility of automatically executing code when a USB stick is plugged in) was solved through Windows Updates for XP, and on 7 it is no longer possible ...
8
votes
5answers
2k views

How can I remotely wipe the contents of a Linux Laptop if its been stolen?

I am currently investigating using Linux Laptops for my development team. We currently run Windows. The one advantage that keeps coming up for Windows over Linux from a system administration / ...
8
votes
3answers
1k views

How to manually check for rootkits on a server

Does anyone have a general step by step list on how to try discover rootkits on a Linux or Solaris server? I'm looking for to to manually find the rootkit, not by automated software. For example: ...
8
votes
8answers
652 views

Battling Malware without spending money

Our environment consists of about 80 users running Windows 7. Previous to me showing up as a full time IT employee, the company had contracted an outsource IT solution. As part of their set up, they ...
8
votes
3answers
3k views

Is CentOS a good choice from a security perspective?

How secure is the CentOS Linux distribution? I noticed there were times when there were no up-to-date patches for some version of CentOS (e.g., 5.6). I read this on some mailing list that I can't ...
8
votes
2answers
434 views

Running proprietary software on Linux safely

As a summer project, I'm looking to prevent any piece of proprietary software like many games I run from have access to my personal files. After looking a lot at sandboxing, I've decided that anything ...
8
votes
4answers
1k views

How does System Memory Dump work?

So there are so many pen-testing tools that perform a memory dump on the system. How exactly do they work - what exactly happens ?
8
votes
4answers
3k views

How to disable Firewire in OpenBSD/Linux to prevent attacks through Firewire?

Since Firewire lacks security, allowing a plugged-in device to access host memory, it's a good thing to fully disable it. If we're not using the BIOS to disable the Firewire port then how could we do ...
8
votes
3answers
1k views

Practical non-government uses of Biba, Bell-LaPadula, etc. models

For example, the Biba model is now hanging out in current versions of Windows. Things downloaded from the Internet are tagged as such. Internet (low) stuff can't alter user (medium) stuff which isn't ...
8
votes
1answer
401 views

What steps do you take to keep both your computer and internet browsing secure?

I am thinking about your browser setup, antivirus protection, vpn, browsing best-practices and so on.
8
votes
6answers
704 views

What is preventing the widespread common use of MAC-type systems?

Overall question what is preventing the uptake of MAC systems such as SELinux/AppArmor in corporate and desktop computing environments? Why don't you think it isn't already widespread? I do not ...
8
votes
1answer
174 views

What is your default umask set to?

What is your default umask set to? Did you run into any problem setting a stricter default umask?
7
votes
6answers
243 views

Why shouldn't I run other applications on a Firewall?

If I want to use Ubuntu 11.04 as a Firewall in SOHO environment, then I just can't figure out what is the bad thing about installing GUI on it (e.g.: XFCE)? The only opened port to the world (wan ...