Securing Linux systems and applications; understanding Linux security features.

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4
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1answer
64 views

What infection vectors is Trojan.Linux.BillGates usually delivered with?

I just discovered that my server is infected with Trojan.Linux.BillGates.G and is being used to launch DOS attacks. It surprises me as the server is kept up-to-date (CentOS/Tomcat/CouchDB) as much as ...
0
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0answers
88 views

My ISP provider is spoofing DNS [on hold]

My ISP provider is DNS spoofing OpenDNS, Google DNS, Norton DNS, Yandex DNS and all other known DNS servers. So even if I use those, I still can't access some websites. So I need a DNS server which is ...
1
vote
1answer
23 views

How to best manage multiple applications using the internet with Firewall

Im not new too Linux (Ubuntu 14.x) however I must admit that I have never bothered with a Firewall until now. Im currently using Ubuntu's inbuilt firewall (UFW) with a graphical plugin (GUFW), which I ...
3
votes
3answers
79 views

Is it safe to manually patch security bugs in an outdated system, that is no longer supported?

How do I manually patch security bugs safely without damaging the system for information security purposes on my Ubuntu system that I am running on my Nook Simple Touch (2011 Nook)? I need to find ...
1
vote
1answer
26 views

On a Linux server, is it safe to store a script containing DBI credentials in the cgi-bin of the DocumentRoot?

I understand that (at least on Linux servers) the custom is to create a ScriptAlias from a cgi-bin directory located inside the DocumentRoot (i.e. /var/www/html/cgi-bin/) to a cgi-bin directory ...
2
votes
2answers
81 views

Is Qubes OS more secure than running a set of activity related VMs?

I'd like to skip the argument about Linux being more secure than Windows, and purely focus on the security boundaries between Host OS and VMs. Is Qubes OS theoretically more secure than say - Windows ...
4
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0answers
37 views

Laptop Encryption variables

If you are running such an operating system as Ubuntu among others, you would of seen that it gives you the polite option to encrypt your Home directory OR Whole hard drive with a robust AES 256bit ...
5
votes
3answers
78 views

Can I test my own network?

I'm currently trying to enter the field of information security and I was just wondering if there was anything barring me from testing my own network for security vulnerabilities? I only have a couple ...
1
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0answers
22 views

web view addjavascriptinterface exploit

I have been banging my head around this for almost 56 hours now (+/- a few that I took out to have a couple of naps and RedBulls) and have not been able to get anywhere with it so far. I am trying ...
3
votes
1answer
63 views

Does posting the technique I used to encrypt my Linux system make the encryption inherently less secure?

I recently encrypted my laptop, but I also wrote notes on how I did it and posted those notes online. The configuration is fairly complicated and, from what I can tell, also fairly unique. I did not ...
2
votes
2answers
52 views

When would group permissions be a security issue?

I frequently hear that 600 and 700 is recommended for security when possible before 660, 770. I'd like to understand the risk that 660, 770 would have that 600, 700 wouldn't.
0
votes
1answer
21 views

Does Dropbear support SSH key revocation?

I'm using Dropbear as an SSH server in my embedded system. I want to know if Dropbear supports SSH key revocation? If yes, how I can do it?
-6
votes
1answer
92 views

Are the only people who can work in security those who were learning from 10 years old? [closed]

I'm a second years Master student in computer science. As time passes, the more my desire to work in computer security increases. I have many friends who are more experienced than I, who told me ...
5
votes
1answer
89 views

After a bufferoverflow does an attacker only have access to calls which are present in the library where the C code was compiled?

Or are there techniques to just get a shell? What I am interested in is if I have compiled some C code using only a small library with insignificant possible calls, does this restrict the attacker ...
134
votes
21answers
21k views

Hardening Linux desktop machine against people from my household

I am looking to make a clean install of a Debian system on my home desktop. To clarify, I am switching from Windows and wish to use it as my day-to-day home OS - I'm not going to be running any ...
3
votes
2answers
76 views

How to forget LUKS keys during emergency?

One day, while Alice is downloading some photos from Bobs server, the alarm goes off. Trudy came to steal all the data. Fortunately, the server is setup to shutdown upon server room alarm and has ...
-4
votes
0answers
73 views

Need help getting Metasploit (MS08-067) to work in Kali Linux 2

I apologize right off the bat for this seemingly common problem, but I cannot seem to resolve it no matter how many fixes I try that I have found from this website and others. I am running Kali ...
4
votes
1answer
151 views

Protecting master password in memory

Assuming I want to enter master password only one time at the start of the program, how is this master password usually protected in memory after that? Is the encryption key after being derived from ...
3
votes
1answer
60 views

Where and how to create secret on embedded Linux system?

I'm using OpenSSL on an embedded Intel Edison (Atom Platform) running an Yocto Linux. I want to store passwords with OpenSSL on the device, but I don't know after which rules I should create the ...
9
votes
1answer
2k views

Does analysing Malicious code in gdb pose a security risk?

I have encountered a Malicious Shell-Code & i have ported the shellcode into a compatible C Code which can run the shellcode, i compiled it using gcc -fno-stack-protector -z execstack shellcode.c ...
2
votes
2answers
99 views

Finding a backdoor on a server?

Let's say I hire someone (freelance), for IT work on an Ubuntu server. The server has a good firewall, I run clamav, chkrootkit & rkhunter scans weekly, and I try to keep good practices. The ...
4
votes
2answers
64 views

Sorting hosts via open ports using NMap

I was tasked with running a NMap scan against our corporate network and compiling a list of only live endpoints. My issue is how to go about separating out the hosts via their open ports (printer/...
43
votes
1answer
5k views

I have the ability to run arbitrary Python code on the 'apache' user. What damage can I do?

So, due to bad programming on the part of one of my former colleagues, one of our internal web apps allows the user to upload and run an arbitrary Python file. This recently came to light via an ...
0
votes
1answer
81 views

Robots trying to login to Azure VM when SSH port is closed in manager

I have many robots trying to do SSH login in a Azure VM. In the resource manager SSH is disabled but attacker IPs are public, as you can see below, where I copy a log for auth.log (I have an Ubuntu ...
1
vote
2answers
64 views

How does allowing breaking grabs with keyboard actions pose a security risk?

While modifying the Gnome Tweak Tool I saw the following option which states that allowing breaking grabs with keyboard actions poses a security risk. How can it be a security risk?
1
vote
1answer
92 views

How to detect zip file encryption algorithm

As we know zip files supports a simple password-based symmetric encryption system and some vendors use other algorithms. I used the zipinfo command in Linux but it doesn't say what encryption ...
0
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0answers
7 views

Can one setup an application whitelist for other applications even encompassing the root user on Linux?

Is it possible to restrict an application program to being used/called only from designated programs without having resorting to specific code testing or wrappers? This restriction has to apply to ...
0
votes
1answer
40 views

Network configuration: Preventing my computer being used as a proxy?

I recently installed an extension for Chrome called Hola (skip to next paragraph if you know it). It calls itself a VPN, but is basically a proxy pool AFAIK. You can choose a country from a list in a ...
1
vote
2answers
69 views

OpenSSH DOS exploit proof of concept [closed]

For some research I'm looking for a working DOS exploit for OpenSSH. The OpenSSH version, vulnerable to the exploit is irrelevant. The only requirement that I have is, that the exploit should work for ...
0
votes
1answer
116 views

Found 0000 Permission Files on a hacked server

Its been a long week trying, at times when I can, to figure out what is happening on a server/website I am maintaining. The site was previously hacked, supposedly cleaned up by previous owners, and ...
1
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2answers
76 views

Lock down OS to specific hardware device

I know everything is reversible. But how could I lock down an instance of linux to a specific hardware device? Possibly tying the filesystem to a specific serial number on the board for instance.
1
vote
1answer
80 views

How important is a static IP address when authenticating with my server?

I am looking to move my business into a small office. I have found somewhere very suitable but unfortunately they cannot provide a static IP address. Currently, to connect to my server from home I ...
3
votes
3answers
51 views

How secure are webservers from linux repos?

how secure are Webserver like Apache2 or Nginx on a current linux, e.g. Debian, when downloaded from a repo of this distro? Of course, they have to configured correct and must be up to date. If they ...
0
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0answers
17 views

What is purpose of fipscheck utility and fipscheck library on Linux?

So I am messing around with dracut and I am trying to get my Linux system in FIPS 140 mode by passing fips=1 to my linux kernel at the boot time from grub. However, I got confused on why dracut ...
0
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0answers
26 views

How crypto module integrity checks mandated by FIPS 140 standard help to make Linux based appliances safer?

After browsing dracut and hmaccalc rpm package source code I found out sha512hmac utility that is used to do do integrity checks for linux kernel (and other binaries) from initramfs boot stage uses ...
3
votes
1answer
50 views

How can I understand this extract, concerning basic heap overflow?

Unfortunately, I dont seem to understand one minor concept in the "Art of Exploitation" book, concerning heap overflow: a new root shell is being added to the passwd file. From page 168: However, ...
1
vote
1answer
16 views

Does altering the routing table to my hub defeat the purpose of a VPN?

I am running a VPN on my server with openvpn. When running openvpn I have a shell script that runs afterwards: ip rule add from 192.168.0.19 table 128 ip route add table 128 to 192.168.0.0/24 dev ...
2
votes
5answers
76 views

Is it beneficial to run the browser from a different user account for personal devices?

On Linux, when launching the browser does it help security if I don't run it from my main user (not root, but still has my personal information in it) as follows: su FirefoxUserName -c 'firefox' ...
1
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0answers
31 views

Error Running command shell :TimeoutError Operation Time out

I am Testing a Payload linux/x86/meterpreter/reverse_tcp in my Test Linux network to Exploit, I got a Meterpreter Session by Metasploit using it, I tried several commands like getuid, cat and all ...
2
votes
3answers
150 views

How can I execute shell in this CTF exercise?

I am playing a CTF wargame and unfortunatley got stuck at this level, so I want to "crowdsource" it. No need for complete answer, but hints would be enough. How can I: Make strcmp to be 0 (evaluate ...
5
votes
2answers
141 views

Is there a reason why /proc/interrupts is world-readable?

Reading this recent research paper on how to use information from /proc/interrupts to attack a system, I was wondering whether there is a particular reason why /proc/interrupts is world-readable. ...
0
votes
0answers
46 views

Why isn't ettercap working

I am working on an ARP poisoning/browser redirection project with Ettercap but even if I follow all the steps right it still doesn't work. I tried disabling firewalls too. What I do is: Start ...
3
votes
1answer
192 views

Air-gap implementation for personal computer use

I recently read over Bruce Schneier's article on setting up an air-gapped computer and am looking to improve my setup (compared to my current "use one Windows PC for everything" model). The main ...
-4
votes
2answers
66 views

Safe to connect a USB to Linux?

A "friend" offerred me a USB with files. I plugged it into my Ubuntu (version 12 or 14, don't remember) PC and an error appeared (don't remember exactly what was written..). So I wasn't able to browse ...
0
votes
1answer
27 views

Using virtual server for backing up files

I've purchased a virtual server which I need to run some custom tools every once in a while. I actually don't use any server features of my virtual server, I really just need a Linux machine which is ...
1
vote
1answer
40 views

How are DNS requests sent when using ovenvpn? Are they encrypted?

I use openvpn in thru the gnome network manager. When my computer is connected to the vpn do DNS requests look like they come from the vpn exit ip or from my real ip? Are the DNS requests sent in the ...
4
votes
1answer
101 views

Hidden service security SSH

Pretend I have a Tor hidden service. For ultimate security I would firewall the internet entirely, except for Tor, to try to reduce IP address leakage and other security risks. My problem is how ...
0
votes
0answers
51 views

Why there is no shell prompt by exploiting this script?

I tried to get a shell prompt in the following vulnerable code, I think that I found the vulnerability, actually it is a simple stack buffer overflow, but now I have a problem with exploiting the ...
0
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0answers
26 views

Process of auditd -s enable/disable persists for a long time

I have setup auditd on my system, with some basic rules from CIS Benchmark paper and the following auditd.conf file: log_file = /var/log/audit/audit.log log_format = RAW log_group = root ...
9
votes
5answers
2k views

Can we trust the information displayed by the linux utility commands for a vulnerable machine?

After checking a vulnerable linux machine for rootkit and deleting them, we need to get some informations about the process , port ,incoming or outgoing connections... , using some useful commands as ...