Unix is a family of multiuser, multitasking operating system that is widely used in workstations, servers and embedded devices. The best-known Unix variant is Linux.

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How can I protect myself from this kind of clipboard abuse?

Clipboard abuse from websites Many websites use JavaScript or CSS to stealthily insert or replace text in the user's clipboard whenever they copy information from the page. As far as I know this is ...
14
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3answers
668 views

Is passing sensitive data through the process environment secure?

Recently I have been looking for the possibility to pass sensitive information from one process to another (at process startup time) without passing it through the command line or without using a ...
12
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7answers
404 views

UNIX Servers: Possible intrusions or attacks that do not use any of the open listen sockets

What type of attacks are there that do not use open TCP or open UDP ports? Is it safe to assume that no open ports means no remote access? (Excluding the possibility that there is a badware already ...
11
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3answers
415 views

Is it insecure to have an SSH server on a workstation?

I know one systems administrator who runs SSH Server on his workstation to push files to it and check things from a phone but I think it is a bad idea for several reasons: An operations workstation ...
8
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4answers
457 views

Does UNIX have a dual approval mechanism?

Sudo and logging is used to keep administrators accountable. But is there a command/configuration that lets you enforce a dual approval type control such as the the "Two Person Concept"? (eg. Two ...
8
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1answer
172 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
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4answers
4k views

OpenBSD vs. NetBSD security

If i search for the two words: OpenBSD and NetBSD on: http://www.exploit-db.com/ then i get 17 hits regarding security bugs on OpenBSD, and 8 hits regarding security bugs on NetBSD. So what are ...
7
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3answers
582 views

What prevents this exploit from working (unix SUID)?

If I have a user on a unix system where Im allowed to create new files, what prevents me from downloading an executable file onto that system which is already SUID'ed to root on a different system? ...
7
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3answers
6k views

How do I ensure data encryption on Samba transmission on *NIX systems?

I have a heterogeneous system (both MS and *nix) that communicates with CIFS/SMB. How can I ensure proper data encryption at the application layer?
7
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2answers
172 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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3answers
153 views

Is it safe to attach a potentially malicious hard drive to a Solaris machine?

We bring in hard drives from un-trusted sources and would like to ensure that they will not contain any harmful content. What kind of risk is there for Solaris? As in, if Solaris is running, and I ...
6
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2answers
301 views

How a malware executes remote payload

Let's assume a malware was installed (on a UNIX-based platform) with some social engineering tricks. The original installed code itself may be benign, but the only malicious activity is that the ...
6
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2answers
1k views

What are the dangers of storing webserver temp files in the /tmp/ folder?

I have configured my first publicly accessible nginx server. I have configured it to use a /tmp/nginx folder to store temp files. This includes the body of http requests, proxy files etc. The /tmp ...
6
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2answers
526 views

How is the available entropy in /dev/random calculated (or estimated)?

It seems (to a non-expert) that /dev/random is acclaimed to be useable as a source of pure random data. However, I am curious as to the analysis of the file /dev/random. /dev/random is a collection ...
5
votes
3answers
211 views

Could browsers improve security of stored passwords by using setuid?

On Unix-esque systems, Mozilla Firefox stores a users' preferences, web history and stored passwords in a set of files that are readible and writeable by that particular user. This makes sense: when ...
5
votes
3answers
758 views

Making passwd/shadow files more secure

The passwd/shadow files in a unix-like OS contain sensitive info such as a user's password. In addition those files aren't necessarily secured: with a live CD we can access those files on the hard ...
5
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2answers
156 views

How is the password prompt going to protect me from ruining my computer?

On Unix based systems, I'm often prompted to enter my password before installing or running a program. Why does this protect me? If I'm running a kiosk, I understand that a password might prevent ...
5
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4answers
2k views

SHA-512 unix passwords. How secure are those hashes, really?

I came across this very alarming sounding thread which indicates a GPU with about half the compute capacity of the GPU currently powering the monitor I type this on is capable of 11.5k c/s. I'm not ...
5
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2answers
125 views

What is the meaning of the term “simple string” for the SALT string in Unix crypt using SHA-256 and SHA-512?

In Unix crypt using SHA-256 and SHA-512 the author, Ulrich Drepper, introduces the SALT string as the following (highlight by me): For the SHA-based methods the SALT string can be a simple string ...
4
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1answer
3k views

what does it mean to be setuid root?

I am reading Tanenbaum's Modern Operating Systems 3e. He says "Suppose that the program being attacked [with malicious code] is SETUID root in UNIX (or has Administrator power in Windows). The ...
4
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1answer
63 views

Dangerous to open a unix socket within www root?

My web server is chrooted into /var/www, and its contents are available over the network. One of my web applications needs access to a unix socket, and so that socket needs to be somewhere in ...
3
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2answers
58 views

What are the benefits of having multiple overwriting patterns for secure deletion? [duplicate]

When installing a new AIX server, there is a possibility to use several patterns for secure deletion. My question: Is it necessary to use several patterns? What is the benefit from having several ...
3
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1answer
4k views

Finding environment variables with gdb, to exploit a buffer overflow

I have to exploit a very simple buffer overflow in a vulnerable C++ program for an assignment and I am not being able to find the environment variable SHELL. I have never worked with BoF before, and ...
3
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1answer
140 views

S/Key as an alternative to UNIX passwords

There is this password system called S/Key I saw on the Internet. Can someone give me a brief description about S/Key and how it works? Can S/Key be an alternative solution to the UNIX password ...
3
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4answers
326 views

What mechanism enforces user permissions in Unix/Linux?

One of the core pieces of security in Unix/Linux systems is limiting privileges by user. For instance, certain actions can only be done by the root user. In theory, this can keep a malicious process ...
3
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1answer
100 views

Is mosh now recommended by the security experts? (2014)

Mosh has been around for a while now. Although it's claimed to be "a replacement for SSH" by its authors, mosh does actually depend on ssh to do the initial authentication, after which an instance of ...
3
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1answer
282 views

OpenBSD-based LiveCD/LiveDVD - is it secure? is it offical?

Does the OpenBSD LiveCD/LiveDVD get deeply audited like the original OpenBSD? Is it an official "port"? Experiences with it?
2
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3answers
389 views

Security Implications of setting passwd as suid

When the passwd command is executed, it runs as the root user. Can't this be exploited? If not, why?
2
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1answer
182 views

is root@localhost the same as Unix root with GUID = 0 and ID = 0?

Is a Mysql root user (root@localhost) the same as the computer root account (GUID = 0, ID = 0) ? I mean, is it the root which is executing the script? How can I know if the users are the same?
2
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2answers
243 views

vulnerable getlogin

I was reading "A taxonomy of Coding Errors" and I have a doubt regarding the point mentioned in C/C++ >> API Abuse >> Often Misused: Authentication(getlogin). I fail to understand the attack vector ...
2
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2answers
316 views

Why superuser or administrator account should never locked?

Why should administrator or superuser account never locked regardless how many incorrect login attempts are made? What should be done instead to alert the staff to the attempted instrusion?
2
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2answers
268 views

unix config scanner / compliance checks

I'm looking for a tool, that scans unix operating systems for configuration issues. E.g. a script that finds PermitRootLogin yes in the ssh config file or with other words: a script that automates ...
2
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1answer
192 views

OBSD X11 as non-root?

If running X11 as root is not a very good idea, then can anyone mention a method/solution, how to still use a GUI, and not having X11 as root?
2
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1answer
125 views

What is a good method to report security breaches that are being used to actively spam?

I received an email the other day purporting to be from a bank I hadn't even heard of, so I decided to poke around. On some quick investigation, it looks like something has just latched onto some poor ...
2
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1answer
94 views

Eavesdropping a communication between a local application and the network

After some digging on the Internet, I've been unable to find a satisfying solution for my curiosity... Here's the thing : using a shell script, I've been able to obtain a list of IP addresses ...
2
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5answers
917 views

Security purpose of asking admin password to mount partition on Linux

So I divided my 250GB laptop drive into 2 partitions and some swap. On the second partition which is an ext4 60GB partition I installed Fedora 17. On the other bigger NTFS partition I've got Win XP ...
2
votes
1answer
318 views

Can UNIX Domain Sockets be locked by user ID?

If I created a folder /tmp/me with permissions 700, and started a process under me that starts a listen socket under /tmp/me/socket. I currently assume that a connection to that socket originated ...
2
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2answers
151 views

Does glibc2 version of the crypt function still use DES for alternative hashing methods?

I'm trying to understand how typical Linux distributions generate the password field for entries in /etc/shadow. I can't figure out what encryption algorithm is being used to produce the encrypted ...
2
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1answer
178 views

unix malicious scripts/ksh execution

I'm wondering whether my architecture poses a security risk. Details: The whole website is not ROOT owned but still, the APACHE user used instead has some pretty advanced permissions. I have a ...
2
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1answer
925 views

Is the mount manpage saying nosuid *is* secure, or is *not*?

I'm a bit confused about the description of nosuid in the mount manpage on this RedHat system I'm setting up: nosuid Do not allow set-user-identifier or set-group-identifier bits to take ...
2
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0answers
99 views

BSD encryption advantages

If someone who knows about the BSD project has a moment to answer this, I'm wondering a few things about the encryption used. It's more than what I'm finding in the docs and on Wiki/Google (even the ...
1
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4answers
9k views

Netcat IP Spoofing

I am connecting to a server nc -v 192.168.0.1 1111 But I want to do IP spoofing because the server on 192.168.0.1 only accepting commands from 7.7.7.7. We are two friends, I am 192.168.1.1, and my ...
1
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2answers
205 views

What's the secure way to change UNIX permissions on a harcoded file often?

I'm writing a daemon that monitors something in the OS and flips execution permissions on a file in /run/ back and forth. The file has static contents and the file name is hardcoded in the daemon. I ...
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1answer
752 views

Can you describe a real-life scenario of exploiting sticky bits?

Sticky bit are mentioned in every UNIX security book, but I couldn't find anyone that describes the exploitation of Sticky Bit set on a file. Can you?
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4answers
92 views

Why can't just any program use his own file-system-access-system?

This may sound stupid for everyone who knows more than me about the UNIX-System and security in software: Imagine you have a program trying to cause harm by deleting files. You just do something like ...
1
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1answer
300 views

Installing applications with different user accounts on linux

I have basic question about installing applications on Linux operating system, using the Oracle database as an example. When installing the Oracle database package, I created a user called ora112, a ...
1
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2answers
373 views

Security issues with an append-only log in UNIX

I'm going over past exam papers for a security module I'm taking at university and there is a question which I can't give a great answer for. As a security manager in a bank you are asked to ...
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1answer
100 views

Notification or report for security problem of unix systems? [duplicate]

I have unix systems(Solaris,Oracle,Redhat vs).I have to control all system for security problem,bugs,patch,vulnerabilities I'm looking for securty information for all security issue After that I'll ...
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2answers
450 views

Sun ILOM / Out of band management security concerns

I would like to get some outside opinion on this if possible, although I do not know what to ask. Sun ILOM is an Out-of-band management system. I understand it is a separate OS on the box that is ...
1
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1answer
127 views

Do I need logging enabled in my rules in IPFW for sshguard-ipfw to work/blacklist ip's?

From the FreeBSD handbook: Even with the logging facility enabled, IPFW will not generate any rule logging on its own. The firewall administrator decides which rules in the ruleset will be ...