Securing Linux systems and applications; understanding Linux security features.

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3
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2answers
124 views

How to securely install software on Ubuntu?

How to install a software like Sublime Text on Ubuntu 14.04 LTS and mitigate against a MITM attack? There is a PPA available, but the PPA must be added manually. I don't see any PGP keys or MD5 ...
7
votes
2answers
254 views

List all files with only arbitrary file path read, but no directory listing nor sudo

I have found a path traversal vulnerability that allows me to read any path on the server that does not require sudo. To fully exploit this, I would like to know which files exist in each directory ...
0
votes
2answers
188 views

Running tails on a corporate computer

Is it safe to run TAILS on a corporate computer? I mean a corporate computer that has hardware cryptography and probably some backdoors; and, by safe, I mean that nobody will be able to recover what ...
0
votes
0answers
198 views

Protecting against bad USB in ubuntu

I am referring to this thread: How to prevent BadUSB attacks on linux desktop Since i want to install ubunto onto a possible infected usbDrive using a live DVD and the installation manager i was ...
4
votes
1answer
6k 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 ...
1
vote
2answers
459 views

Debian encryption is as safe as Truecrypt. Is this correct?

When I try to install latest debian to my pc, the wizard ask me to input a password to do FDE(full disk encryption). My questions are: What algorithm does Debian use? (Truecrypt = AES) Can I change ...
0
votes
1answer
58 views

SELinux ignoring /etc/sysconfig/selinux directive

I'm running SELinux on CentOS 6.5. In /etc/sysconfig/selinux I have set SELINUX=permissive. But everytime the system starts, sudo getenforce shows SELinux as Enforcing. What could be causing it to go ...
0
votes
2answers
176 views

Is openVZ patched against all exploits for its current kernel version?

I am looking for a container vitalization software that will allow me to create containers that will house specific software/jobs/tasks which I can start stop at will (and bind to interface aliases). ...
3
votes
2answers
369 views

LUKS nuke efficiency

I am wondering about LUKS nuke patch efficiency. In fact, I think I don't really understand it. From what I know of LUKS, a passphrase is used to encrypt a random key (the master key), which is used ...
0
votes
2answers
4k views

Exploit failed [unreachable]: Rex::ConnectionTimeout The connection timed out(remote host ip)

I keep getting this when I start to exploit, trying to exploit my xp machine but this keeps happening, I can not find the fix anywhere, I don't believe I am the only one getting this.. I am a ...
0
votes
0answers
81 views

Secure password transfer from stdout to another window

I am currently trying to build a little, secure password manager. As of now, I've implemented the encryption. Each website has its own file and each file has a number of fields (Most commonly username ...
1
vote
3answers
446 views

Cracking passwords after a pattern with John

So I am trying to find out how easy it is to crack a password using some great Linux tools. We all know about John as a password cracker and how great it is. But how about specifying a pattern. ...
9
votes
1answer
133 views

Security measures and anti-virus on server to mitigate acting as a propagation vector

We have a web application for which I've been asked to add the ability to let users upload documents that will then be visible and downloadable by other users. Those documents will typically be images ...
4
votes
1answer
161 views

Is Linux's 'W' command a security breach?

I was surprised that the out of the box 'W' command on Linux provides so much information without needing any SUDO or admin permissions. In particular, the command shows the command line of each ...
3
votes
2answers
78 views

Copy Metasploit from Linux to Mac OSX? [closed]

I'm just wondering is there anyway to move Metasploit framework from Linux to Mac completely and It will be work ? and if yes , how ?
7
votes
5answers
2k views

Fastest way to “lockdown” CentOS and have network intrusion detection, firewall, etc up and running?

Are there any proven concepts or "installers" to get up and running based on the best practices securing and locking down a CentOS installation? I'm hoping for an automated tool that would scan the ...
2
votes
2answers
80 views

Ubuntu/Debian Is it okay to use a sudouser account as my primary on a workstation?

This question comes to you from the the common WindowsNT advice that "I", as the computer administrator, should login with a normal unprivileged user account for day to day use. Does this concept have ...
1
vote
0answers
162 views

Limit Packets Per Second

Since last week I have been seeing something fishy and it seems to be worsening. I tried many firewalls and they seem to be useless. I blocked all unwanted ports and only few ports are open so I found ...
2
votes
2answers
122 views

Can a virtual machine be used instead of the host?

I was thinking of using a Debian guest as my main 'host' instead of my actual host (Ubuntu). Do you think this will have any advantages in terms of making it difficult for digital forensics to ...
12
votes
3answers
4k views

Using TPM with DMcrypt?

Is it possible to use TPM for storage of some private key? It's not a full-disk encryption , I want it to be compatible with existing LUKS, just add another key, and store it in the TPM.
9
votes
2answers
11k views

Is it possible to use the aircrack-ng tool to crack a WPA2 Enterprise network?

is this tool (aircrack-ng) capable of cracking into a WPA/WPA2 Enterprise network? This tool has major success cracking the passwords of WEP/WPA networks. If it can, how, but if not, is there another ...
11
votes
3answers
2k views

Which Linux kernel vulnerabilities allow installing a kernel-level rootkit?

My question is related to vulnerabilities that allow installing a Linux kernel-level rootkit (for example, to modify the execution flow inside the kernel; for return-oriented attacks; or to modify ...
0
votes
2answers
53 views

Ubuntu backup to only specific devices

I am looking into setting up a secure Ubuntu server with daily backups to two different external hard drives that will be swapped with the external hard drive that is stored in a safe deposit box. ...
15
votes
1answer
826 views

Linux /etc/shadow password change security

I wonder what happens what happens when I am changing my password on a Linux system. Basically all passwords are stored in a file called /etc/shadow or /etc/master.passwd in BSD-like systems as I do ...
0
votes
0answers
90 views

Blocking IP After multiple connection with Netsh advfirewall to mitigate DDos

Hello I wanna block Ip address if they exceed 20 connections with port 80 TCP for HTTP Server. I wanna do this using Netsh advfirewall, In Linux I use IPTables: iptables -I INPUT -p tcp --dport ...
1
vote
1answer
133 views

Domain socket authentication as in MySQL and PostgreSQL secure?

Are authentication mechanisms based on UNIX domain sockets (Linux) secure? And more specifically, are the respective MySQL and PostgreSQL implementations on Linux secure? The background for my ...
0
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0answers
40 views

how can I authenticate a process from kernel side?

I would like to authenticate and integrity check a single process before its execution. That authentication and integrity checks should be on kernel side for obvious reasons. I was thinking to add ...
-2
votes
2answers
150 views

Cannot get simple shellcode runner to work [closed]

I'm just trying to execute shellcode directly from the command line. I send a simple 0x90 NOP and get a segmentation fault? root@server:~# gcc shellcode.c -o shellrun -fno-stack-protector -z ...
6
votes
2answers
2k views

Hacked Ubuntu server, probably hacked commands (netstat, ps, …), how to replace them? [duplicate]

An Ubuntu server of my company has been hacked to carry out a DoS attack. I found the shellshock bug had not been fixed by my colleagues, and I think it's the problem. Then, I found an ELF file that ...
1
vote
3answers
106 views

Moving /boot to USB and Preventing booting from other USB devices (Allow boot from only one USB)

I'm going to move my /boot/ folder to a USB to as a security measure to protect against Full Disk Encryption exploits. My question is, is it possible to only allow boot from USB from a single USB ...
0
votes
0answers
198 views

How to add basicConstraints extention to a self signed certificate

Using openssl to create a self signed certificate. The certificate needs to have the Basic Constraints value defined and showing in the cert but I can't seem to be finding the right location to modify ...
1
vote
3answers
383 views

Removing a Redirect Virus from Fedora Linux

Despite several attempts listed below certain websites are getting redirected to a certain ad website automatically, out of the blue on linux. When some website starts redirecting to this ad website ...
4
votes
2answers
199 views

Do `sudo` and `su` belong to capability-based security?

In Linux, do sudo and su belong to Capability-based security ? For example, when editing a system file, we usually need sudo or su to temporarily switch to user root. Does this example belong to ...
-1
votes
1answer
116 views

how to gain root access to linux machine? [closed]

I am a security auditor and I have faced the following situation: A development company that has a group of Linux machines gives limited access to their users. They asked me to find out all the ...
0
votes
1answer
141 views

Joomla Linux Permissions

I installed Joomla 3 to /var/www/html directory in Cent OS 6 server. Currently /var/www/html is owned by apache:apache. What is the recommended permissions for Joomla installation on Linux in ...
9
votes
3answers
2k views

Security tradeoffs of pathname-based MAC (e.g., TOMOYO, grsecurity, AppArmor, …)

I have been learning about MAC (Mandatory Access Control) systems in Linux. Often, but not always, these are tied to Linux Security Modules. Some systems I've looked at: SELinux, Tomoyo, AppArmor, ...
1
vote
1answer
125 views

How to forbid one directory only in TOMOYO (2.5)?

(For example) I want to restrict write access to /home/backup from anybody, except a particular backup script. (To protect from accidental deletion.) For this, I suppose, it is enough to have two ...
0
votes
1answer
222 views

Is there an AES 256 LUKS encryption option in Fedora? [closed]

I have certain information on my drive that I don't want anyone (not even me ;) ) to gain access to. I read recently that Fedora only offers EAS 256 LUKS encryption. This just isn't secure enough ...
0
votes
1answer
323 views

iptables intercept received packet with proxy and then forward to destination

Lets say I receive internet through my eth1 port and share it via hotspot to other devices (wlan0 port) [internet]----(eth1)[my computer](wlan0 hotspot) | ...
2
votes
2answers
75 views

Are default ACL in Linux a security flaw?

I'm currently learning the Linux system and I have a question about the default Linux ACL. On my virtual machine, all files created are set with the default permissions as follows: -rw- rw- r-- ...
1
vote
1answer
125 views

Notifications (RSS or mailing list) of CVE with high scores for Windows and Red Hat? [closed]

I'm looking for a RSS feed or a mailing list that would allow me to be alerted of new CVEs impacting Windows or Red Hat that have a very high score, such as the recent ones for Shellshock and Winshock ...
0
votes
1answer
106 views

Do you really have to go to the extremes this guide says? [duplicate]

http://lifehacker.com/how-can-i-stay-anonymous-with-tor-1498876762 Alright, so here's a lifehacker guide on how to remain anonymous. Do you really have to go to this high level of extreme to remain ...
12
votes
3answers
3k 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, ...
5
votes
3answers
1k views

What are the risks of making ether-wake available to all users?

The Linux ether-wake utility, which creates a magic packet to wake on lan another machine, requires root access: $ether-wake 12:34:56:78:9A:BC ether-wake: This program must be run as root. To give ...
2
votes
1answer
84 views

Downloading operating systems vulnerable to TCP amplification

I am doing a security research project on TCP amplification, and was looking to download vulnerable OS's for testing. From what I have researched mostly ancient linux kernels (2.0.x and below) and ...
4
votes
1answer
1k views

Can this be a DoS Attack?

When I'm checking my log, I found like 15k events of " PAM service(sshd) ignoring max retries; 6 > 3 " I know this might be normal, and considered as Brute-Force attack, but can it be classified as ...
28
votes
2answers
3k views

Do simple Linux servers really need a non-root user for security reasons?

Playing devil's advocate, Let's assume I purchase a Linux server from a hosting provider. I am given a password for the root user and am told I may login using SSH. The only purpose this server has ...
2
votes
1answer
85 views

Will setting a password for a linux login increase security?

I created a user that I use to login with using an SSL Key. I have not set a password. To be clear it is not an empty password, but an unset one. The /etc/shawdow has a single exclamation point ...
17
votes
6answers
4k 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 ...
2
votes
2answers
278 views

Writing errors to Apache's log file from PHP - are there any pitfalls?

I'm updating an application to write slightly more verbose errors to the system log file (in this case, /var/log/apache2/mysite_error_log). I hope that I'm not asking the proverbial stupid question ...