Securing Linux systems and applications; understanding Linux security features.

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3
votes
2answers
102 views

Decoding injected PHP malicious code in my server

I've found on internet similar issues, and I compared the code. This one is different. I recently found out that the CentOS LAMP webserver we use for development in our office was infected by a piece ...
0
votes
1answer
54 views

Test the security of my Linux setup [closed]

I have a Ubuntu installation running in VirtualBox. I have made a few modifications to it (some kernel modules and startup scripts) that I hope would make it very secure. Is there anyway I can test ...
2
votes
1answer
75 views

Linux antivirus and files bigger then 4GB

I wish to scan files that are bigger then 4GB. For example video files. I noticed many antivirus software are limited to a maximum of 4GB (ClamAV for example). So: Is there a antivirus software ...
4
votes
1answer
39 views

Is protecting a parent folder secure enough to protect files within that folder?

So this topic came up during a hardening exercise on Unix/Linux machines where a parent folder was marked with chmod 740 but files within that folder were marked chmod 644, and the argument went that ...
-4
votes
1answer
47 views

Hydra saying cracking done and displaying random passwords

I have Hydra on my Linux machine. I want to test cracking security with Hydra on SMTP but I get no success. After about 20 messages that SMTP mechanism and a random message like [465][smtp] host: ...
0
votes
2answers
75 views

Is there a tool to detect what technologies a website uses? [closed]

I'm looking for the name of a tool I've used a long time ago, that for a given URL/website address would extract the technologies used for that site. For example that the site is running Apache, using ...
1
vote
1answer
78 views

Can a root user inside a Docker/LXC break the security of the whole system?

My question is probably more about the LXC than about Docker, but I wonder what are the security mechanisms to prevent a root user inside a Docker image to access the whole host. More precisely, I ...
3
votes
3answers
152 views

What should I be aware of when opening my home server to the internet?

I've built a home server (pretty much just a basic PC with a couple of big HDDs) which I would like to use as an FTP server and a minecraft server. Both would be for members of my gaming community. I ...
0
votes
1answer
109 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
votes
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
92 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
votes
4answers
176 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
96 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
votes
1answer
70 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 ...
-1
votes
4answers
192 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?
1
vote
1answer
473 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"). ...
12
votes
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
votes
2answers
92 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 ...
-2
votes
1answer
87 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
votes
1answer
63 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
vote
2answers
131 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
votes
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
votes
1answer
38 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
vote
1answer
56 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
89 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
votes
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
72 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
44 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
80 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
66 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
vote
1answer
76 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
votes
1answer
105 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 ...
-1
votes
1answer
39 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
votes
1answer
78 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
votes
1answer
146 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
135 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 ...
1
vote
2answers
110 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 ...
0
votes
0answers
37 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 ...
4
votes
2answers
202 views

Decrypting SSL using Wireshark 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 ...
3
votes
0answers
47 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
vote
1answer
45 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 ...
12
votes
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 ...
14
votes
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
votes
2answers
81 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
96 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 ...
-4
votes
1answer
111 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
80 views

How to detect arp spoofing using iptable? [closed]

How can I set iptables to detect arp spoofing on linux?
1
vote
2answers
72 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
165 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
57 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 ...