Securing Linux systems and applications; understanding Linux security features.

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11
votes
1answer
644 views

Help in understanding an application's crash - exploitable?

Being new to researching vulnerabilities in native applications (as opposed to web apps), I'm having difficulties understanding a crash in Debian's browser, Epiphany (version 2.30.6), and determining ...
1
vote
1answer
307 views

Configure Wireshark to capture preformatted data from pseudo-device

So, for a research project, I'm trying to use the HONE project on github, which creates during its module installation two pseudo-devices in the /dev folder. These are called hone and honet, the ...
2
votes
2answers
300 views

How to protect source code that resides on virtualbox web server which starts at boot?

I installed CentOS 6 on a 3gb virtualbox disk. It hosts a web server which starts automatically when the OS boots. No user login required. When it boots, it is given an IP and the host machine can ...
3
votes
5answers
438 views

Blocking network access to host(s) at the kernel level in Linux?

Getting it out of the way: Not iptables! What I'd like to do is block network access to certain IPs, subnets, and/or hostnames at the Linux kernel level, such that no user, including root, could ...
2
votes
1answer
808 views

What is the actual value of disabling remote root login using ssh?

I have read the answers regarding why you should disable remote root login, but there is something nagging me. Assume this: Scenario 1: Remote server A. Remote root login disabled. Password ...
16
votes
1answer
13k views

Configure SSL Mutual (Two-way) Authentication

A lot of tutorials, a lot of pages, a lot of question and they differ in implementation of this issue "Configure SSL Mutual (Two-way) Authentication". I have to do it with Linux, and I don't know from ...
26
votes
3answers
6k views

Is it appropriate to use haveged as a source of entropy on virtual machines?

While looking for solutions to entropy pool depletion on virtual machines, I came across an interesting project called haveged, which is based on the HAVEGE algorithm (HArdware Volatile Entropy ...
4
votes
1answer
359 views

Exploited by newbie3viLc063s

My debian server got exploited by some scriptiekiddie who used Newbie3viLc063 http://pastebin.com/jma8JRG1 . Scriptkiddie uploaded logo_php.png to my server (My permissions sucked :s) and he did run ...
5
votes
2answers
687 views

Using 'sudo vim' to spawn a shell

I've recently read here an answer from a user about the way he hacked a server in a CTF contest. At some point in the description, he said that he did sudo vim and then spawned a shell via VIM using ...
3
votes
1answer
413 views

Bypass va_randomize_space and stack-protector

Is a program compiled with the GCC -fstack-protector option and running in a Linux environment with the va_randomize_space kernel variable set to 1, totally protected against buffer overflow attacks? ...
13
votes
2answers
685 views

Getting exploit reliability when using the off by one framepointer overwrite on linux

We have a program that is vulnerable to a one byte frame pointer overwrite. The stack is marked executable, the Linux machine has aslr disabled, stack cookies are disabled, and it's a little endian ...
1
vote
2answers
195 views

Is this Scenario Exploitable?

Here is the scenario: You get to overwrite 4 (consecutive) Bytes of a Userland Remote Process in Linux without Exploit Mitigation and without the ability to inject any Shellcode and you know the ...
5
votes
2answers
1k views

Securing USB flash drive on linux

We have a industrial system(running on linux) with a USB port. We have the USB port only for copying certain data. Other than this we don't want the USB drive to contain any other executables or ...
5
votes
2answers
1k views

Linux forensics questions (ssh config, user activity)

I'm a linux noob and have an assignment I'm a bit stumped on... We're given VirtualBox (vdi) images and raw files for the state of a linux server at 3 different dates. We're supposed to answer: ...
2
votes
1answer
157 views

Force all user processes to be ptraced

I'm implementing a ptrace based tool for logging system call use. It is much more simple than strace, but I'm doing this so I can learn how these tools work. I'd like to trace all user processes since ...
2
votes
2answers
108 views

What kind of privacy leakage do stuff printed to stdout pose?

1- When a program outputs to stdout, is that normally logged anywhere else? 2- When is it an issue to make a command verbose in printing to stdout instead of working quietly or redirecting to a file? ...
1
vote
1answer
808 views

Pre Installed OpenVAS , light way Linux [closed]

Is there any Pre installed light way OpenVAS Linux distributions Or any light way Linux witch Openvas Tested on it and work properly on that Linux distribution ? I have used Back Track (UBUNTU ...
3
votes
3answers
1k views

Using /usr/bin/passwd as login shell

I have a requirement to set up a SSH tunnel between two hosts. SSH server runs on a Linux host, and the SSH client (PuTTY) runs on a Windows host. I have set up a separate user account (say 'tunnel') ...
2
votes
1answer
848 views

Can exploit vulnerability if program started with gdb, but segfaults if started without gdb

i'm currently trying to exploit a simple program called basic_vuln.c #include <stdio.h> int main(int argc, char** argv) { char buf[64]; strcpy(buf, argv[1]); } I'm using xubuntu ...
-4
votes
1answer
89 views

LUG war games — suggested strategies? [closed]

My LUG on campus once in awhile holds a mock wargames on a VM. I'm trying to figure a way to get root access and make everyone else not be able to have root (king of he hill). I have a few ideas, but ...
7
votes
6answers
2k views

Using linux to combat windows flash drive malware?

I just put an old flash drive which i used with a windows machine into my linux. I noticed many files, mostly exes which were never visible in windows (my windows does not hide hidden files and ...
-2
votes
2answers
869 views

How to completely password protect login into Ubuntu 12.10?

I am running Ubuntu 12.10 on my laptop and I would like to make a set up such that without a login password, no one would be able to login into my system. Currently it seems that one can, quite ...
1
vote
3answers
5k views

Retrieve auto saved Skype password from Ubuntu 12.04 LTS

The email address I used to create Skype profile has been disabled and I can't get it back. Unfortunately, I don't remember the Skype password now. As the password is auto saved in my local machine I ...
3
votes
3answers
740 views

Proper Linux user authentication through PAM aware applications

Currently I'm building an authentication system using Linux PAM for a python daemon process. It will need to authenticate remote users from a variety of front-ends against the local user list. ...
39
votes
4answers
7k views

Should I change the default SSH port on linux servers?

Is there any advantage in changing the SSH port, I've seen people do that, but I can't seem to find the reason why. If you have a strong password and/or a certificate, is it useful for anything? ...
1
vote
1answer
241 views

Dual Linux System with Whole Disk Encryption

(This is a continuation of my question on Ask Ubuntu.) My goal is I want to have a Xubuntu/Ubuntu dual boot, with a catch - I want the disk to be fully encrypted with the dm-crypt (native supplied) ...
3
votes
1answer
1k views

Tacacs+ scenario: can I permit user to configure only for one interface and deny others

I'm currently deploying TACACS+ with a Cisco device, I use a TACACS server from here: http://www.shrubbery.net/tac_plus/ My scenario is: I want to permit a user to configure my router but only for a ...
4
votes
2answers
1k views

Is GPG suitable as part of a password manager and generator?

I assume that GPG is very strong to crack, guess, etc. Since I have confidence in GPG, would it be appropriate to use my GPG key as the master key for a password manager or generator?
2
votes
2answers
7k views

Test firewall rules (Linux)

I have a question about how to test the firewall rules. To be more specific, for academic purpose I have to set up a machine which will accept all kind of packets o a specific interface. I added an ...
1
vote
3answers
806 views

How to Detect Zimbra Sniffing Trojan

I am a sys admin of our system, we are running zimbra as email server in our environment. I got the following message from the CEO. "Everytime I send or receive an email - I get a SPAM ads a few ...
2
votes
1answer
311 views

tshark - dump the data section

As the name suggests, im trying to dump the data section of the packet, man would suggest that its something like tshark -r file.pcap -t fields but im not having any luck
1
vote
3answers
1k views

Best practices for firewall hardware

I'm planning to implement a linux based firewall/router with at least 6 x 1Gb NIC's (network with ~300 computers/server with >=8 VLANs) Can anybody recommend hardware best practices (reference to ...
1
vote
1answer
784 views

How configure tomcat 7 SSL to use AES-NI?

My server has AES-NI and I would like tomcat 7 to make use of this but I am not really sure how to make that happen or where to even start looking. I am quite familiar with tomcat administration, and ...
0
votes
2answers
210 views

Tracing root compromises

In regards to the following: 0day Linux/CentOS SSHd Spam Exploit — libkeyutils.so.1.9 SSHD Rootkit There apparently seems to be a bunch of redhat server being backdoored via a library. Does ...
1
vote
1answer
95 views

Does pppd encrypt traffic?

There is pppd program that can be used to create point-to-point conections over various channels (including other network). It supports authentication and compression. But does it encrypt traffic or ...
4
votes
2answers
3k views

Need advice on linux server being hacked

I'm currently trying to find out how one of our centos servers was compromised. We were experiencing malware on our sites. After searching I finally found the malware injecting into the sites. As it ...
12
votes
5answers
2k views

Apache/Linux server, DoS attack from own IP

I have an unusual problem I've been trying to diagnose for a while: It's about a Debian server running a custom compile of apache 2.2 with PHP, Red5, MySQL 5.5 (standard binary), sendmail (distro ...
1
vote
4answers
2k views

Why do I need both root password and user password in Fedora Linux?

I am just now installing (for the first time) a shiny new Fedora 18. I set up a strong root password, installed the whole thing. Now it is asking me to create a user account and a password is ...
5
votes
1answer
163 views

Hidden directory with 0x0d0x0a

Someone has hidden a directory to fool policies on a FTP account. The directory name was 0x0d0x0a. How did the user create a folder with that name? The directory is nearly invisible with ls but ...
0
votes
2answers
352 views

Is there an easy way to secure Apache on debian?

I run an Apache webserver with lots of PHP-sites of several customers. I tried install apache-mod_security2 after this (german) tutorial that is using these rulesets: ...
4
votes
3answers
1k views

Restrict access to a specific directory on Linux

I want to limit access to a single directory on the hard disk (log files) to few processes (log files for a single process for example). All processes run under the same user, so file system access ...
5
votes
3answers
4k views

Wine or sandboxie as sandboxes

I'm looking for a sandbox for Windows. I've looked at sandboxie but I don't know if it delivers what it promises. Is it actually safer to run programs inside sandboxie ? I know a full-blown VM could ...
1
vote
1answer
102 views

set uid for reboot binary & pm-suspend : security hole?

I think all the question is in the title : For the use of my laptop to be more convenient I made a chmod 4755 to /sbin/reboot and /usr/lib/pm-utils/pm-action so I don't have to make a 'sudo' before ...
5
votes
3answers
609 views

Live Linux which does not mount any hard drive in the computer

I am searching for a Linux System which runs from a CD and does not mount any hard drive of the computer. I want to prevent any possiblity to write something on the hard drive of the computer and on ...
1
vote
1answer
2k views

Retrieving saved password from Firefox on Linux [closed]

I know there are ways to get the cookies from browsers in Windows and retrieve and decrypt saved passwords from them. Is there a similar way to do so on CentOS?
9
votes
2answers
9k views

Is it possible to use the aircrack-ng tool to crack a WPA2 Enterprise network?

is this tool (aircrack-ng) capable of cracking into a WPA/WPA2 Enterprise network? This tool has major success cracking the passwords of WEP/WPA networks. If it can, how, but if not, is there another ...
1
vote
2answers
288 views

Linux kernel 3.2 syscalls

Just trying to get the assembler instructions for <__execve> of the code below because i want to build the shell spawn opcode list: #include <stdio.h> int main() { char *happy[2]; ...
6
votes
2answers
254 views

Process authentication for Linux

Is there any possibility to authenticate a running process in Linux to be sure that this is the original/right one? I know that an Linux operating system is only that secure like the way you use it. ...
0
votes
1answer
183 views

Different types of segmentation faults in Linux [closed]

In Linux, when the NX-bit triggers the segmentation fault seems to be "error 15", whereas a more typical error, such as attempting to read from invalid memory, results in "error 7", (seen from dmesg ...
5
votes
2answers
4k views

Pitfalls of SSD encryption

Encrypting an SSD is a process that is sometimes warned should be done with caution. E.g. http://en.gentoo-wiki.com/wiki/DM-Crypt_with_LUKS mentions how the SSD may keep hidden space used for wear ...