Questions tagged [security]

Content related to computer security., i.e. content about policies, mechanisms, etc. needed make sure data is not leaked or corrupted and services available in all circumstances.

Security of Unix & Linux systems. If your question is about balancing the pros and cons of a security policy, you may be interested in the IT Security site.

Computer security deals with ensuring three properties:

  • confidentiality, i.e. data is not leaked

  • integrity, i.e. data is not corrupt, data is received as it has been sent in the correct destination

  • availability, i.e. a given service is available under all circumstances, for example, it's resilient to Denial of Service attack

For some systems, for example in cars or airplanes, another insteresting property is the safety. This is the warranty that the system will not put human life at risk while running or because it does not function properly.

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Books/Guides for Securing a Server

I have a website idea I want to build and launch, and I'm thinking of getting a small VPS to host it (I like Linode for their price, and they seem to be widely recommended). I'm pretty broke so I can't afford a managed server. I downloaded Ubuntu…
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Have I been hacked?

I run a dedicated server, where I noticed a high CPU usage recently, and checked the processes. It appears someone (mick account) was mining on my server. How is this possible? The process is below. I have suspended the account. What else would I…
Booboo
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Lock some accounts during some time periods

Is it possible to lock some accounts in order to be accessible only during specific time periods? For instance the account joe should only be accessible during office hours.
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Why is it a security problem to have /usr/sbin owned by bin?

The Sendmail Installation and Operation Guide (§1.3.1) asserts: For security reasons, /, /usr, and /usr/sbin should be owned by root, mode 07552[...] 2Some vendors ship them owned by bin; this creates a security hole that is not actually related to…
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Where can I "hide" easter eggs for students learning about Linux security?

I feel like this isn't the best place to ask this (since there's no single right answer), but I can't think of a better place. If you have a better recommendation, could you please recommend it and I can move the question rather than just having it…
loneboat
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What are the methods to protect home folder files from other applications runing as the same user?

I would like to enforce the security access of some files in my Home folder. My concern is about processes running with the same privileges as me having access to those files. I've been wondering about this for some time, because the role based…
S182
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Do any of the Linux anti-virus applications protect against Linux specific threats?

It is well known that as a target for viruses, and other exploits Linux compares favorably to other operating systems. However there are a number of known Linux specific threats. There are also a number of mostly commercial anti-virus products for…
Ben
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How to import the official Tor GPG keys?

I am trying to install the latest Tor Browser Bundle on Arch Linux: $ makepkg --syncdeps --install [...] ==> Verifying source file signatures with gpg... tor-browser-linux64-4.0.8_en-US.tar.xz ... FAILED (unknown public key 2E1AC68ED40814E0) ==>…
l0b0
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Hiding work in account with multiple users

I'm currently working on an assignment in a cluster programming class. The class has been given an account on the cluster, so we can ssh in and do our work. The problem is that the one account is shared among everyone in the class. Each student just…
oadams
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Overwrite deleted file

I have deleted a file on a FAT16-formatted flash drive with rm. I can see that the file is still recoverable using testdisk or fls. Is there a way to securely delete the (already deleted) file, without destroying other data on the flash drive?
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Where are the total tmouts stored in AFL?

In American Fuzzy Lop, I can see: total tmouts : 16 (5 unique) But where is the input that made the 5 unique tmouts? I cannot find it in the output dir :\
Hessnov
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SHIBBOLETH SP - Shibboleth handler invoked at an unconfigured location - Shibboleth.sso/Session/

On Ubuntu 14.04LTS, I am trying to get shibboleth configured. When I go to https://mysite/secure/index.php, it works properly, I can authenticate, etc. but when I go to https://mysite/Shibboleth.sso/Status (or any other…
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How can I create an SSH login that delegates to telnet securely

I'm playing around with the idea of creating a MUD, but one of the down sides is that they use "telnet" which is insecure. I'd like to retain the ability for "anonymous" users to access a specific account, and the only they that account does is…
Daniel
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SC_ERR_NOT_SUPPORTED(225) with Suricata on CentOS 6.5

I have just installed installed Suricata 2.0.3 RELEASE on CentOS 6.5. I try running it with sudo suricata -c /etc/suricata/suricata.yaml -i eth0 and get the following warning - [ERRCODE: SC_ERR_NOT_SUPPORTED(225)] - Eve-log support not…
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Has my machine been compromised?

I have a bunch of lines in my machine if I use "ps aux". Here are the lines: samp 8413 0.0 0.0 968 564 ? S 12:28 0:00 ./ssh 150 samp 8419 0.0 0.0 956 380 ? S 12:28 0:00 ./ssh 150 samp 8420 0.0 …
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