Securing Linux systems and applications; understanding Linux security features.

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4
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2answers
107 views

Is there a way to check for “hollow” processes, or malware hidden within “normal” processes

I recently came across an article on the The Verge, which centers around the concept of commercial malware production and how it's used around the world. The article introduced me to a number of ...
2
votes
1answer
72 views

How does the Samba misconfigured '/etc/passwd' file security bypass vulnerability work?

I just found this vulnerability on http://www.securityfocus.com/bid/36363/references, which affects several samba server 3.0.xx. Can anyone explain more about this vulnerability? How this bypass ...
1
vote
2answers
100 views

About SHA1 in default Disk Encryption in Linux

Link to the Thread: Recommended options for LUKS (cryptsetup) I wonder what's the exact difference between SHA1 and SHA512. I know that SHA512 has a longer key but I've read that it doesn't matter ...
0
votes
0answers
28 views

Bruteforce with Hydra [duplicate]

I'm trying to use a Hydra script in the following scenario on localhost and Linux: After web form login, my app redirects to another page with header(Location: internalpage.php) I use this syntax ...
5
votes
2answers
636 views

Security of Linux Full Disk Encryption (Ubuntu / Mint) -insecure?

I'm wondering, why is Ubuntu and Mint using SHA1 for Full Disk Encryption? I heard several times that SHA1 shouldn't be used anymore because it is weak and it could be cracked. Could you guys ...
2
votes
1answer
84 views

Upload a file into directory with public write access

I know it is not right to set a permission for the folder as 777, but if it is done so will it be possible to upload a file into that directory without ftp access ? Here is what I mean Lets say the ...
3
votes
1answer
94 views

Key generation: Differences between GnuPG classic, stable, modern?

I plan to create a 4096 bit RSA&RSA key pair: gpg --gen-key --personal-digest-preferences SHA512 --cert-digest-algo SHA512 Is there any difference in generated key quality between versions 1.4 ...
1
vote
0answers
66 views

Is there any security risk with adding a **root's** public key to the local user's authorized_keys (so root to login as a user non-interactively?)

Background: I want to try unprivileged lxc containers a try on my small web server (hosting 2-4 users). Since the server is shared among friends, we decided to separate our services from the machine ...
3
votes
2answers
114 views

Firewall egress filtering / quick whitelisting

Suppose your Aunt or Uncle is easily fooled by phishing attempts and their computer has multiple root kits and key loggers running. Assume their computing habits will never change. Looking at his ...
0
votes
0answers
107 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 ...
0
votes
2answers
102 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
1answer
27 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 ...
3
votes
2answers
75 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
189 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 ...
-1
votes
1answer
220 views

ARP: Forwarding or dropping with IPTABLES

So, I ve been trying to ARP Poison my home computer and router (Intended to learn and discover the networks bahaviour). And with success. The whole time I ve been using: with ...
0
votes
0answers
66 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 ...
3
votes
2answers
156 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
431 views

Tails OS for Android and PC?

Can I use Tails OS on a USB-stick on both an Android tablet and a PC, or do I have to have two different versions? Would I have to go into the BIOS to make this work?
3
votes
2answers
59 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 ?
4
votes
1answer
149 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 ...
2
votes
2answers
73 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
85 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
83 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 ...
9
votes
1answer
93 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 ...
21
votes
3answers
2k views

Linux-based Turla trojan

There are several articles describing the newly discovered Linux-based Turla trojan. But basically, all these articles repeat the same, very limited, information. Can anybody provide more details, ...
15
votes
1answer
763 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
2answers
87 views

Safe to use setuid with absolutely no input?

I have a shell script which syncs some files from a remote source and I have a pretty typical HTTP server set-up. There is a user who owns the files served by the HTTP server and a user which runs the ...
0
votes
0answers
74 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 ...
0
votes
0answers
33 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 ...
-1
votes
2answers
106 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
79 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
105 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 ...
0
votes
1answer
41 views

Are paravirtualized drivers a security risk?

Below is a copy of my answer that I gave in some other thread (Would running VMs inside of VMs be a more secure way to study viruses, etc?) about a topic of security of nested virtualization. I would ...
0
votes
2answers
1k 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 ...
-1
votes
1answer
92 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 ...
1
vote
3answers
190 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 ...
1
vote
1answer
47 views

Security implication of non-free drivers

I was wondering what the security implications are of using non-free drivers on a linux laptop. Especially for graphics and wifi.
0
votes
2answers
106 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). ...
0
votes
1answer
115 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 ...
2
votes
2answers
56 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
66 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
152 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) | ...
0
votes
1answer
88 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 ...
2
votes
1answer
72 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 ...
2
votes
1answer
270 views

How does SELinux affect the Linux Kernel networking stack?

I'm interested in how SELinux effects the processing of packets through the networking stack. I've found the following questions and answers: Network policies under AppArmor/SELinux Filtering ...
5
votes
3answers
910 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 ...
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 ...
2
votes
1answer
78 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 ...
2
votes
2answers
141 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 ...