Securing Linux systems and applications; understanding Linux security features.
1
vote
3answers
206 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
2answers
550 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
73 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 ...
4
votes
3answers
218 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 ...
0
votes
1answer
217 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?
5
votes
2answers
1k 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
159 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
112 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
101 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
726 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 ...
6
votes
2answers
245 views
Filling the disk with random data prior to encryption?
Filling the disk with random data prior to encrypting it will supposedly make it harder for the attacker to perform any cryptanalysis. Most sources seem to state this is because it will be harder for ...
10
votes
1answer
230 views
Slot machine segfault: what can we determine?
We walked into a casino and saw this near the entrance. I don't have a specific question, but is there anything that would be interesting to share and explain from the image?
4
votes
1answer
247 views
What tools can be use for Security Auditing for Redhat
Are there any good tools that can be used for Security auditing of Redhat Linux.
That can audit all the critical areas of System and provide the detailed output of all the audited sections.
15
votes
3answers
416 views
+200
What can an attacker do with Bluetooth and how should it be mitigated?
What are the security risks of Bluetooth and what technologies and best practices should be used to protect my device? What can an attacker do once a malicious device is paired with mine?
...
3
votes
2answers
214 views
Restarting nginx with Jenkins or Phing - is it safe to allow Jenkins to run sudo without prompt for password
I am implementing the recommendations from Integrating PHP projects with Jenkins for my own PHP projects.
I have created a jenkins user in my ubuntu 12.10 server. I used Phing as my build tool and I ...
3
votes
4answers
190 views
What mechanism enforces user permissions in Unix/Linux?
One of the core pieces of security in Unix/Linux systems is limiting privileges by user. For instance, certain actions can only be done by the root user. In theory, this can keep a malicious process ...
0
votes
3answers
119 views
How to retrieve a site whose server is running Linux
I'm struggling to find a way to retrieve through Google a list of sites having Linux as their server operating system.
Actually, I'd like to be able to test the following command:
nmap -O ...
2
votes
2answers
110 views
Is it possible to boot into root's /bin/bash on a LUKS encrypted device?
I have to check the possibility of case mentioned in the title. An average Linux could be booted up into root's terminal directly without authentication by modifying kernel boot parameters.
I'd like ...
-1
votes
2answers
731 views
Is there a linux laptop equivalent to dsploit for android? [closed]
Is there a linux laptop equivalent to dsploit for android?
I am particulary refering to it's MITM functionality.
3
votes
2answers
117 views
Safely remove an expired PGP key file
since it's possible to recover a deleted file I wonder how one can safely remove a PGP key file (with linux's command line tools) so that it's impossible to recover it. Maybe some dd command? Searched ...
2
votes
1answer
100 views
Trust linux images burned from untrusted systems
For securitys sake I'm assuming my system is successfully compromised after a targeted and/or non-targeted attack.
I've downloaded some linux images and burned them to do a re-install.
Since I can't ...
1
vote
1answer
61 views
How to forbid one directory only in TOMOYO (2.5)?
(For example) I want to restrict write access to /home/backup from anybody, except a particular backup script. (To protect from accidental deletion.) For this, I suppose, it is enough to have two ...
4
votes
1answer
157 views
“WICKED” entries in the default nginx vhost's logs
I have a small VPS running nginx, and for a long time now (several months, since I rented it) it has been collecting weird entries in its default (listen 80 default;) vhost's logs:
109.x.x.121 - - ...
3
votes
1answer
190 views
What are some steps to take for securing a Linux server that aren't in this list of obvious ones?
Obvious things:
Disable root login (rather, don't enable it)
Secure SSH (no root login, key auth only, timeout after inactivity, whitelist users who can SSH in, etc.)
IP Tables firewall whitelisting ...
1
vote
3answers
150 views
Protect linux kiosk display
We use a small computer with linux attached to a big tv to display some data to the public.
Normally, there is no keyboard connected. When a keyboard is connected at boot, we start the configuration ...
5
votes
4answers
201 views
HOWTO : Email encryption in a browser
I have read about encryption and I think it's a good idea for me to encrypt my email. I run ubuntu 12.10 and use Firefox for browsing.
In my quest for learning how to use gmail/hotmail to send and ...
3
votes
2answers
510 views
Impact of Mathew Garrett's Secure GRUB Bootloader on UEFI Secure Boot
My eyebrows rose with Matthew Garrett announcing his Secure GRUB Bootloader less than three hours after no longer being a Red Hat employee. This work and its impact on the trust chain design of the ...
0
votes
1answer
104 views
SSH Log: “Accepted password for user…”
I have only port 29999 open for SSH connections. But in the log file I see entries like this:
Accepted password for user1 from 190.101.200.100 port 55805 ssh2
saying that a connection was accepted ...
3
votes
1answer
153 views
How do I configure Terminal Server (and clients) for use over untrusted Wifi networks?
Suppose a client wants to directly connect to Terminal Server exposed to the Internet, without a VPN, ... what software & settings is needed to properly protect against WiFi based attacks? ...
12
votes
4answers
331 views
How to safely synchronize time over Internet?
All modern OS now keep accurate time by regularly synchronizing time over an untrusted network - Internet. Could an attacker conducting a MITM attack, influence or change the time of a computer while ...
5
votes
1answer
4k views
TCP Peer unexpectedly shrunk window messages in dmesg log
We get quite few messages like these in our dmesg log on various servers.
TCP: Peer 0000:0000:0000:0000:0000:ffff:d431:5861:56369/80 unexpectedly shrunk window 2522304441:2522312601 (repaired)
TCP: ...
0
votes
0answers
124 views
TrueCrypt Windows FDE Multi-Boot [closed]
I tried to achieve Matt's setup in my VM with Ubuntu and Debian (both having their separate /boot partition). Everything worked smoothly, but enabling TrueCrypt-FDE on Windows, I could still access ...
2
votes
1answer
115 views
Why must VMX instructions trap?
What would happen if each of these instructions didn't trap into VMX root when executed in VMX non-root?
INVEPT, INVVPID, VMCALL,VMCLEAR, VMLAUNCH, VMPTRLD, VMPTRST, VMREAD, VMRESUME, VMWRITE, ...
1
vote
2answers
156 views
What's the secure way to change UNIX permissions on a harcoded file often?
I'm writing a daemon that monitors something in the OS and flips execution permissions on a file in /run/ back and forth. The file has static contents and the file name is hardcoded in the daemon. I ...
2
votes
1answer
115 views
Consequences of using -s and -d arguments in iptables
We are studying iptables for a Computer Systems Security course. We are confused as to what happens when the -s and -d arguments are both used in the same rule, such as:
iptables -A OUTPUT -s ...
0
votes
0answers
100 views
How can I find out what is doing a “Trojan.Agent-252697” [closed]
I've scanned my computer with clamAV which has found one file infected with Trojan.Agent-252697. I've of course immediately removed the file, but I have no idea how can I find out what does this ...
0
votes
0answers
368 views
John the Ripper Jumbo Compilation Errors on Backtrack [closed]
Any ideas on the compiling errors? I'm on BT5R2. (also, side note, anyone know how to contact via the openwall community? I looked and didn't see a way)
make clean linux-x86-opencl
rm -f ../run/john ...
1
vote
3answers
285 views
Online security check via command line
My scenario is that I have a VPS with Apache (mostly for development of my own projects) accessed via SSH; and I time to time I would like to do a quick check just to be sure that there's no potential ...
83
votes
8answers
4k views
Attacking an office printer?
I did an nmap scan on an advanced office printer that has a domain name and is accessible from outside the corporate network. Surprisingly I found many open ports like http:80, https:443, and ...
2
votes
2answers
201 views
Possible implementations of networked+encrypted filesystem
Is it possible to implement scheme where remote server just share its filesystem (or resizable container file in it) and it's locally encrypted and mounted? And what is best practical method? (On ...
3
votes
1answer
52 views
auditing mod security rule sets
Is there a audit system that can help me try my strings? Such as user agents, post/get data, a simple way to test general sql injections to see how my rule sets hold?
I know with fire fox I can ...
1
vote
1answer
235 views
Why does the OpenSSH client on Mac OS X silently launch an ssh-agent for the user?
I'm confused by the difference in behavior of ssh clients I'm seeing on two different hosts. Just to be clear, this is the scenario:
"macbox" OS X using OpenSSH_5.2p1 ssh client
"sunbox" Solaris 10 ...
5
votes
2answers
297 views
How can I use nmap to distinguish between a normal linux machine and an android device?
According to this link: here, nmap 5.2 onwards is now supposed to detect android smartphones. I am using nmap 6.01 but it only identifies android devices as running a linux kernel.
4
votes
3answers
90 views
Can the root of a system access to unencrypted data when using a double tunnel?
I connect to a DMZ gateway system (B) which is not secured. From this machine (B) I can connect to the final destination (C).
A-->B-->C
I created a ssh tunnel from A to B and forwarding the port 22 ...
4
votes
3answers
769 views
What key does Linux use when storing user passwords?
Linux typically stores user names and password hashes in /etc/passwd or /etc/shadow.
Now lets say I have an old CentOS distro and I want to attempt to recover a user's password (it's in a legal, ...
3
votes
1answer
78 views
Do public keys make Kerberos more secure (RFC4556)?
We're using IPA to centralize our authentication and I found an option to add a public key for each user. After doing a little research I found this to be an extension to Kerberos 5, RFC4556.
From my ...
2
votes
1answer
336 views
Victim system's internet connection slow after ARP spoof?
I've been using Nemesis 1.4 to test ARP spoofing on a local victim machine. I've been spoofing both the victim machine and the default gateway to ARP redirect to my machine.
Spoofing victim's source ...
0
votes
2answers
203 views
Any open source software firewall with country based ip blocking feature? [closed]
I am looking for an open source firewall with country based ip blocking feature for Linux OS.
7
votes
2answers
202 views
How a malware executes remote payload
Let's assume a malware was installed (on a UNIX-based platform) with some social engineering tricks. The original installed code itself may be benign, but the only malicious activity is that the ...
0
votes
0answers
1k views
Open Source (Software Firewall + Unified Threat Management - UTM) for an Linux Dedicated Server Hosting [closed]
I am newbie in managing Linux Dedicated server. I am looking for Best Open source Unified Threat Management solution with Firewall Support and it should need to be managing through an web GUI ...
