Securing Linux systems and applications; understanding Linux security features.

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1answer
131 views

Online vs offline backups [closed]

Up to this point I was using physical hard drives for backups, typically using dm_crypt as mentioned here. If online storage is used instead, and the provider cannot be trusted how much should the ...
0
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0answers
8 views

How to prevent future attacks from Trojan.Agent.Linux.A? [duplicate]

One of our servers was just infected by Trojan.Agent.Linux.A (see https://www.virustotal.com/en/file/ca22002822b27562971b1b12bfd61f2f670554ebdb0907270fda4a65f7fd2eed/analysis/1448647113/). I am ...
-1
votes
2answers
178 views

How to limit source port for accessing blocked website?

My country has a firewall which blocks sites like Facebook, whatsApp etc. However, they use some kind of port blocking, so some important websites for me like Chegg is also getting blocked I think due ...
3
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4answers
232 views

How Likely Is It For A Virus To Spread From A Linux VM To The Windows Host

I'm currently running Windows 10, and I plan to use a Linux distro to run in a VM (Virtual Box). I know Linux is one of the most secure operating systems there is and I'm curious as to how likely it ...
5
votes
2answers
146 views

Securely decommissioning a dedicated server

One of my dedicated hosting CentOS servers hit 12 years. I received an end-of-life notice on it, and I started receiving SMART errors as well. I guess it's time to let it go. But before I do, I'd like ...
-2
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1answer
75 views

Use the Shellshock vulnerability to get a root console as a normal user [closed]

Owner is root and also made a Set-UID for the following code snippet: # include <stdio .h> void main () { setuid ( geteuid ()); system ("/ bin/ls -l"); } How might the Shellshock ...
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4answers
500 views

How can I use netcat like ping?

How can we use the netcat (nc) to determine whether a particular machine is running web, mail or SSH services?
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1answer
534 views

ClamAV Flagging application .swf files as malware

ClamAV scans on our application servers are identifying some of our legitimate Flex .swf files as malicious, specifically citing CVE-2015-5548 (specifically, "Swf.Exploit.CVE_2015_5548 FOUND"). ...
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4answers
1k views

When using multiple operating systems, can they affect each other?

Let's say I have two different OS on my PC, Windows 10 and Linux. It is well-known that Windows collects a significant amount of information and sends it to Microsoft's servers, but I wonder if it ...
5
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2answers
140 views

Is it possible become root through a broken symlink owned by root and globally writeable?

I'm looking for a vulnerability on a server. I'm looking in the /var directory and I get something like this: drwxr-xr-x 3 root root 4.0K Aug 14 21:02 kerberos drwxr-xr-x 12 root root 4.0K Nov 11 ...
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votes
1answer
95 views

Honeypot used as as a proxy?

I'm running Kali Linux on my system at home to practice pentesting. If I implement a honeypot on my system could it be possible to use that as some sort of proxy server? I was thinking it wouldn't be ...
2
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1answer
87 views

Give only execute permissions to a Linux binary (prevent inspection)?

I'm writing an assignment for a security course, and I'm trying to create an executable which students can interact with (ie, execute), but not inspect. In particular what I'd like is for them to be ...
1
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2answers
278 views

Validating security log configuration (rsyslog and syslog-ng) for PCI DSS 10.5

I work for a Level 1 merchant with annual onsite QSA audits, so this is a huge deal. PCI DSS 10.5 requires the entity under test to "Secure audit trails so they cannot be altered". In our Unix and ...
15
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8answers
4k views

Why is it possible for the root user to delete the logs?

I always thought the greatest benefit of the logs is to confirm to you that your machine has been hacked. However I see hackers bragging about "rooting" servers all over the Internet. Whats stopping a ...
2
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1answer
48 views

Running rkhunter on Linux

Currently each time before an application and after an application is either installed or updated including regular patches, the command rkhunter --propupd is run, followed by the command rkhunter ...
1
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1answer
76 views

Debian 8 and few questions about Graphical Firewall?

I have installed Debian 8 today, and so far so good. What I want to achieve now is to install firewall but can't find Firestarter in repos (discontinued ?). So, I have installed a GUFW and set it up. ...
2
votes
3answers
122 views

Linux File Security when connected to internet [closed]

Let me first admit that I am a nobody in computer security - I just know the various threats generally known to public. I have a Linux Cent OS 7 installed on my computer which is connected to the ...
6
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3answers
1k views

How to securely read a physical memory address in Linux?

I am trying to read a physical memory address in a device running embedded Linux with our application. The widely suggested method is to use mmap, convert it into virtual address and then read the ...
2
votes
1answer
81 views

Run fuzzer on any service or process in Linux

I have seen examples of fuzzers to submit different inputs to some application or port. How can we run fuzzers on services or processes like any background process for any application? Any ideas or ...
3
votes
1answer
45 views

Prevent snapshots of VPS

Pretend I have a server. Is there anyway to prevent (or make more difficult) the administrator from taking snapshots? Feel free to give me a software way, or suggest if I should change server types; ...
1
vote
1answer
108 views

Automate certificate signing in Linux

In a private network I wish to automate signing for new clients/servers. Something like this: New client is created (dockers & etc) The client create a new private key and a CSR The client send ...
1
vote
2answers
95 views

Ettercap Remote Poisoning

I have a question about one parameter and that's it. When I'm doing DNS spoofing I have to use arp:remote. Can someone explain to me what arp:remote means? I read the man page, but did not ...
1
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1answer
106 views

Yersinia raw packet

I'm using Yersinia to pentest my network. There are two options send raw packet and creating DHCP rogue server I don't understand fully. Can someone explain the meaning of these options?
3
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1answer
140 views

Do major linux distributions differ with regard to releasing security patches? [closed]

For a non-commercial user, is there any difference between major distributions regarding the time needed for security patches to be available? Does the "enough eyeballs effect" takes places in this ...
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1answer
44 views

SSLStrip with autologin [closed]

What can I do to sniff the traffic by SSLStrip when the user has automatic login to the site?
4
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1answer
106 views

RSA fingerprint automatic change or have I been hacked?

today I tried to connect to my Digital Ocean VPS through Putty(kitty) as usual, but I got the message that the server's cached fingerprint had changed, and that it could be a security compromise. I ...
5
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2answers
239 views

Can CVE-2015-7704 - ntpd kiss-of-death affect NTP time servers or just clients?

As the ntp.conf file on a linux server can be setup to allow the system to act as both a client to the public servers and a time server source for local systems am I correct in assuming that it (the ...
4
votes
1answer
142 views

Mitm attack problem [closed]

I have a problem with implementing this attack. I have a kali linux machine on vmware workstation. My router is - 192.168.1.1 My victim ip is - 192.168.1.254 arpspoof -i eth0 -t 192.168.1.1 ...
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vote
2answers
168 views

What are some Linux commands for genrating and verifying digital signatures?

I am attempting a workflow to exemplify the process of digital signature using asymmetric cryptography. If I understand correctly then the public key and the private key in an asymmetric ...
2
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0answers
52 views

What is the security value of chattr +s?

Most modern Linux file systems support extended attributes. +s is secure deletion which ensures (at least intends) that the data in a file is overwritten with zeros when the file is deleted. Some ...
5
votes
2answers
337 views

Decrypting SSL using Wireshark on Linux vs Windows

I'm working on decrypting my own traffic that gets sent through Wireshark and I've been following this guide for reference. I have been using the SSLKEYLOGFILE environment variable and I can get the ...
2
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0answers
52 views

Wayland Partial Encryption for Mouse / Keyboard? (Also X and RDP)

Question What are the best practices for implementing Partial Encryption, to encrypt just the input devices (mouse/keyboard, etc), not the actual video display, during remote desktop sessions using ...
1
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1answer
48 views

What is the risk of data being recovered from SAN storage after logical deletion?

The specific scenario involves Linux servers on VMware hosts with SAN storage. If files containing sensitive data are deleted by Linux, can they be recovered by a low level tool similar to what might ...
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3answers
1k views

What security measures should be taken when running a Linux web server out of our office?

I am interested in running our company's web server from our local office. The office makes use of file sharing and NAS devices among other common office protocols. The worst case scenarios I've ...
13
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3answers
2k views

Breaching security of a notebook with full disc encryption when screen is locked

I am using full disc encryption on my portable computer (running Ubuntu). The setup requires me to enter a password during the boot sequence to access fully encrypted hard drive. There is no ...
2
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2answers
111 views

Prevent Plain-Text Passwords Output by a Script From Being Accessible in the Future

Let's say I have a Bash script that generates a password, creates a new user with that password, and then tells me what the password is: # Generate a password and set it to $PASSWORD PASSWORD=$(tr ...
4
votes
1answer
152 views

LUKS TPM disk encryption attacks

Is it possible, or are there any known attacks, to get the encryption key for disk encryption tpm-luks? (Linux LUKS using encryption key stored in TPM) I know that there are attacks like cold boot ...
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votes
1answer
129 views

Hacking into a simple linux server [closed]

I'm very new to hacking in general so I wanted to learn more. I have an exercise, whereby we have a raspberry pi with a simple website on it and we have to get a file and the stored gpg private key on ...
0
votes
1answer
131 views

How to detect arp spoofing using iptable? [closed]

How can I set iptables to detect arp spoofing on linux?
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2answers
163 views

Will a wildcard SSL work properly for an A record subdomain pointing to another domain/website?

Client has wildcard SSL for his domain/subdomains. The application we are building is on one of our linux servers using one of our IP addresses and is contained within an account named ...
4
votes
4answers
179 views

Should I format storage after buying it?

I've just bought a new (unused) external HDD. Should I format it or is it save to use it directly? Did it already happen that a device was infected before the first customer use? Will formatting ...
2
votes
1answer
73 views

Properly solving IP leaking from WebRTC and other apps with STUN when using a VPN

This is really a follow-up question from this: Stun scripts/webRTC IP leaks I'm connecting to a VPN using a virtual adapter, which has a default routing rule so all traffic goes through it. I still ...
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0answers
220 views

Converting Metasploit module to standalone Python script [closed]

How easy is to convert Ruby code to Python code and to change Metasploit module into standalone Python script for Linux?
1
vote
1answer
97 views

Is it possible to disable `ypcat passwd`

We have an old NIS setup which, at geological speed, is being replaced by a Kerberos one. In the meantime, all the (non-root) users can simply type ypcat passwd and get the hashes of all the users' ...
0
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2answers
73 views

Testing shellshock with PHP

I have been trying to test shellshock vulnerability on PHP similar to this answer. I am running Apache server with PHP running as mod_php. The PHP version is 5.3.10. I have a phpfile (phptest.php): ...
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2answers
148 views

$chsh command security with Set-UID

Why does $chsh have to be a Set-UID command? What are the vulnerabilities of a normal user changing his/her own shell from perhaps bash to zsh? Any help would be greatly appreciated!
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1answer
99 views

Understanding HTTP response from Linux Server

I am working through a question that involves someone using a vulnerability in a Linux server in order to gain access to it. The first part of the question states In monitoring the network activity ...
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2answers
59 views

Prevent fake gateway device attached to PC's network card

Office. Several PCs with Linux. Internet is limited on gateway level, so nobody could do POST-requests over HTTP. We prepared several measures to prevent data leakage on infrastructure level, but ...
7
votes
2answers
291 views

Prevent ARP spoofing with dynamic static entry on Linux

ARP spoofing detection/prevention seems to be quite popular here. With other techniques like port stealing aside, I'm wondering if the following could work to prevent it: Whenever my Linux ...
5
votes
1answer
179 views

Automatically enumerate missing patches on penetration test

Nessus, when running a credentialed scan can check patch levels and return vulnerabilities when a package is one that hasn't been updated to the latest, non-vulnerable version. What is a good way of ...