Securing Linux systems and applications; understanding Linux security features.

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GNU C Library getaddrinfo() Flaw

As you probably already know, this Tuesday a potentially catastrophic flaw has been identified on glibc function called getaddrinfo(), which performs domain name lookups, contains a buffer overflow ...
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1answer
171 views

What are the advantages and disadvantages of installing an operating system through network? [duplicate]

Netboot is a technology that allows a computer to boot through the network, instead of starting on a hard drive, USB stick or DVD, it connects to a remote server to retrieve a disk image to start. It ...
4
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1answer
88 views

Will installing a Graphical User Interface in a server be a security problem?

I'm not a CLI-lover, sometimes I prefer to do some tasks in a server using a GUI rather than using the CLI (it speeds up my work), but I don't know if installing a GUI and accessing it using VNC and ...
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2answers
247 views

A question about arpspoof command

The arpspoof command will spoof default_router_ip's MAC address on all victims in the subnet arpspoof -i <NIC> <default_router_ip> How does it fool the router about the MAC addresses ...
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2answers
87 views

Making a file immutable (against kernel exploits)

I'd like to know how to make files completely immutable. "Completely" refers in this case to: immutable while the system is running. I could live with something like physical access where someone e.g ...
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0answers
67 views

Is that a way break Linux user password by bypassing grub protected?

The best way to delve into others Linux machine is by editing the grub. Many will start by, editing the line ro quite splash as rw init=/bin/bash during the startup (usually by pressing button e on ...
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0answers
17 views

Where can i find information about Ipsec Xfrm framework?

I have searched online and found very little information about the ipsec xfrm framework, including the book Networking implementation and Theory.. Where can i get more information about xfrm ...
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1answer
65 views

Linux distribution on USB stick used to banking for begginers [closed]

Is it good idea to use up-to-date Linux on USB stick instead liveCD to online banking? What is the best Linux distribution for not advanced people who commonly use Windows to make online payments ...
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0answers
80 views

OSSEC error “agent_control(1750): ERROR: No remote connection configured. Exiting”

I am new to OSSEC and trying to figure the tool to deploy it. I have an ubuntu server where I downloaded and installed the security onion packages. I have a few windows systems which I would like to ...
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1answer
60 views

Open Root File Using Other Users “.bashrc -> .profile” [closed]

If I have access to .bashrc -> .profile for another user which is owned by root with lrwxrwxrwx permissions How could I capture /root/flag.txt? It's a Live CD. Thanks
2
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1answer
197 views

Return-to-libc attack with the argument read from registers (EDI/RDI)

I've read that to make a successful return-to-libc attack, the attacker should store the address of the command (for example /bin/sh) in the stack exactly after the return address of the system ...
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1answer
35 views

rpm package info leak?

On Linux, rpm -qi <package-name> command would display the package info, which would contain information of build machine - Build Host :<host-name> Does this pose any security risk? Is ...
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1answer
284 views

IPtables Linux Firewall and IPsec traffic

Can iptables filter out incoming datagrams that are IPSec-tunneled packets going to port 25?
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1answer
5k views

What is real-world impact of CVE-2016-0728 (Linux Kernel Vulnerability)

Today emerged report about another serious vulnerability in opensource world, CVE-2016-0728. It is local privilege escalation in Linux kernel 3.8+. What are the the possible real-world exploitation, ...
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1answer
19 views

Linux equivalent to Windows WriteProtect key in the registry for a software based write blocker?

I unfortunately don't have access to a physical write blocker and am looking for a software based write blocker in Linux. In Windows this can be achieved by modifying the registry and setting a DWORD ...
2
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1answer
163 views

Linux responds to ARP requests for other interfaces - could this be a security vulnerability?

Linux responds to ARP requests on all interfaces by default. To explain, say you have this setup: Client 1 ---> [eth1] server [eth0] <--- Client 2 And the server's eth1 IP is 192.168.1.1 and ...
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0answers
74 views

XCCDF check with SCE - Suse Linux Enterprise Server 11

I have written some compliance checks for Red Hat based systems with XCCDF. Some of my checks are OVAL definitions others are shell-scripts. It works great. The same checks don't work on an SLES 11 ...
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5answers
2k views

Should I use a second/dedicated IP address for SSH?

When running a public web server (e.g., with Apache), I've heard it's recommended to bind SSH to a second IP address, different from the one Apache is listening to. But for me it seems like this is ...
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1answer
534 views

samdump2 Error reading ControlSet: _RegOpenKey

I copied both SAM and SYSTEM files from my Windows7 OS, and then used this command to read the content of the SAM file samdump2 SAM SYSTEM > mdp_chiffres.txt, but i'm getting this error Error ...
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1answer
114 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?
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2answers
141 views

Linux kernel security bugs and hardening Ubuntu? [closed]

I recently read some article about the linux kernel having vulnerabilities, I can't recall exactly where. Being new to linux, do you guys have some references on how I should prevent remote access to ...
5
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2answers
143 views

Security implications of android rooting

I know this question has been asked many times, but I didn't see a clear answer to it from security experts, or it is from several years ago and things might have changed. My question is double: ...
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5answers
5k views

Java SecureRandom doesn't block? How?

I know from experience that reading from /dev/random blocks when the Linux kernel entropy pool runs out of entropy. Also, I've seen many articles and blog entries stating that when running on Linux, ...
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1answer
152 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 ...
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2answers
207 views

Secure Android app development [closed]

I'm beginning with Android App development and I want to make sure that I'm taking the proper security precautions since most apps will handle sensitive data. What security precautions should be ...
0
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1answer
59 views

Is it safe to host passwordless web applications/software with web GUI in Virtual Machines

I have a Linux Mint Virtual Machine which I use quite a lot with my Windows host. I have lots of Software installed there (mostly with web GUI so I can access them from host easily). So I am ...
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1answer
93 views

Can a brute force attack be certainly prevented on a unix/linux shell?

I've been getting kind of curious about computer security. I know brute force has been discussed a fair bit on Stack, but I want to elaborate a bit by asking, "Is it possible to /certainly/ stop ...
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2answers
94 views

Protecting account ssh keys from root

How can users ssh private keys be protected from root stealing and attempting to brute force them? I cannot use selinux as the vendor will not support the app when it's in use? Thanks
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1answer
111 views

Hacked debian server alternative boot

The server of a customer has been hacked last night. It is a standard debian distribution with mysql, apache and ssh for remote access. The way it has been hacked is very peculiar. The standard URL ...
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8answers
15k 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? ...
10
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1answer
295 views

Using TPM with well-known SRK/owner passwords?

First, I will explain roughly how I plan to use the TPM: I am using something called tpm-luks which stores a key in both TPM NVRAM and adds the key to one of the LUKS keyslots. The initramfs then ...
4
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3answers
4k views

How Tor, Privoxy, Vidalia and Polipo are getting together?

I realized that these applications are frequently used together. What is the role of each software in the mission of anonymity and privacy on the web? While I understand Vidalia is a GUI provider, I ...
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2answers
3k views

How to view all SSH authorized_keys for a unix server

How would I view all the authorised SSH clients from a unix server? I know that cat ~/.ssh/authorized_keys shows authorised keys if logged in from root. Can other users set their own authorised keys ...
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3answers
4k views

Can I do hacking using Windows OS? [closed]

I have searched the web a numerous times but haven't found an explicit answer to my question. I've studied (at school and on my own) computer networks for 2 years, doing active programming for 4 years ...
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0answers
83 views

From xss to rce in client side [closed]

I found a desktop application in Linux w/c getsvand that displays items from site xyz. xyz is vulnerable to XSS and code injected there is also executed on client side's desktop app.similar to this ...
3
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1answer
70 views

Blocking all incoming traffic, will it still accept a response from a request I initiated?

I am a 'newbie' when it comes to firewalls, but I am trying to launch some machines that will connect to Facebook's Graphs API. I only want these machines to contact Facebook and nothing else. By this ...
1
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1answer
68 views

MitM attempt resulting in ICMP redirects

I am trying to 'man in the middle' a device on my wifi network. I have configured it to use my Linux machine (also in the wifi network) as a default gateway. On the Linux (attack) host, I switched on ...
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5answers
764 views

Home Banking, antivirus safe environments OR Linux on virtual machines?

Which is the safest way to do home banking, given that I do use Windows on a tablet, I do connect to both private and public networks and I cannot use a Linux live distro right now? I've been ...
6
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1answer
142 views

Is there any security risk allowing regular Linux users to run arbitrary code?

I'd like to allow untrusted users to run arbitrary Node apps. If I use iptables to block everything except trusted servers, make each user's home folder only visible to them, and use runuser to start ...
1
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1answer
111 views

security updates for embedded firmware Tomato (router) [closed]

I installed on my Linksys router Tomato firmware. I saw and now don't understand how security updates work. It can't be that there is no vulnerability since 2010. Tomato Firmware v1.28.1816 ...
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1answer
202 views

Is BSD more secure than GNU/Linux? [closed]

BSD controls the OS while Linux is just a kernel. BSD is less popular than Linux, but which one is better in terms of security?
3
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1answer
101 views

IPSEC End to End Tunnel Throughput

I have established a IPSEC tunnel ( standard configuration , with ESP) , on two Linux machines (centos6 , core i7) communicating over 1 gbps LAN , and i'am checking the communication throughput. It ...
6
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2answers
183 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 ...
0
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1answer
58 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 ...
4
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2answers
226 views

How do shared hosts protect different sites?

I host all my websites from a single VPN, and am about to sell some limited space of my Linode to a friend to host their new blog. It'll simply be another entry in Apache, and then a dedicated folder ...
23
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5answers
5k views

environment variable accessibility in Linux

Perhaps this is a trivial question, but how accessible are environment variables in Linux between different users? e.g. if Alice executes export FAVORITE_FOOD=`cat /home/alice/fav_food.txt` Can ...
4
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1answer
62 views

Protect sensitive information in a password-free, shared database

I'm working on a webserver that stores resources in Redis. To make swarm-deployments as hassle-free as possible, I'm implementing an option where the server doesn't need to access the filesystem to ...
4
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1answer
146 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 192.168.1.1 192.168....
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0answers
77 views

Practicing with return-2-libc exploits

I am trying to reproduce a return-to-libc for a simple vulnerable program. The tutorial is taken from https://sploitfun.wordpress.com/2015/05/08/bypassing-nx-bit-using-chained-return-to-libc/ I made ...
42
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2answers
6k views

What is happening now with the Grub backspace key security vulnerability?

I have just read an article about a new Grub vulnerability. The article said that you can bypass the password protection by pressing backspace about twenty eight times. I am a security guy and I am ...