How to mount iso files without writing it to CD/DVD ?

If you have downloaded a *.iso file from a website (for example, any Linux OS distribution), you can view the content of the iso file without writing as an iso to a CD or DVD as explained below using mount -o loop.. Please note that a loop device is a pseudo-device which will make an iso file accessible to the user a block device.

Syntax: # mount ISOFILE MOUNT-POINT -o loop
$ su -
# mkdir /tmp/mnt
# mount -o loop /downloads/ubuntu-9.04-desktop-i386.iso /tmp/mnt
# cd /tmp/mnt
# ls -l

For mounting you need to be logged in as root or you should have sudo permission. Read below to find out how to mount iso file as regular non-root user.

Reference :

How To Mount and View ISO File as Root and Regular User in Linux

Simple step to check CGI Vuln on Nginx and how to fix it

Only adding this script on your /etc/nginx/fastcgi_params

# Fix Http_proxy a cgi app Vulnerability
fastcgi_param  HTTP_PROXY  "";

and you have  done.

But if you only want to check it on your server but you dont have mod cgi, just follow me :

 

http-proxy-welcome

 

1. Install fcgiwrap, su nginx support feature cgi

apt-get install fcgiwrap

After the installation, the fcgiwrap daemon should already be started; its socket is /var/run/fcgiwrap.socket. If it is not running, you can use the /etc/init.d/fcgiwrap script to start it.

Now open your vhost configuration file…

vi /etc/nginx/sites-enabled/default

… and add a location /cgi-bin {} section to the server {} container:

server {
[...]
location /cgi-bin/ {
# Disable gzip (it makes scripts feel slower since they have to complete
# before getting gzipped)
gzip off;
# Set the root to /usr/lib (inside this location this means that we are
# giving access to the files under /usr/lib/cgi-bin)
root  /var/www/html;
# Fastcgi socket
fastcgi_pass  unix:/var/run/fcgiwrap.socket;
# Fastcgi parameters, include the standard ones
include /etc/nginx/fastcgi_params;
# Adjust non standard parameters (SCRIPT_FILENAME)
fastcgi_param SCRIPT_FILENAME  $document_root$fastcgi_script_name;
}
[...]
}

Reload nginx:

/etc/init.d/nginx reload

Next we create our cgi-bin directory – /var/www/html/cgi-bin because we defined root /var/www/html; in the location /cgi-bin {} container:

mkdir /var/www/html/cgi-bin

Now we place our CGI scripts in it and make them executable. For testing purposes I will create a small Hello World Perl script (instead of hello_world.cgi you can also use the extension .pl -> hello_world.pl):

vi /var/www/html/cgi-bin/hello_world.cgi
#!/usr/bin/perl -w
# Tell perl to send a html header.
# So your browser gets the output
# rather then <stdout>(command line
# on the server.)
print "Content-type: text/html\n\n";
# print your basic html tags.
# and the content of them.
print "<html><head><title>Hello World!! </title></head>\n";
print "<body><h1>Hello world</h1></body></html>\n";
chmod 755 /var/www/html/cgi-bin/hello_world.cgi

Open a browser and test the script:

http://yourdefaultwebsite/cgi-bin/hello_world.cgi

and you will see “Hello World” on your browser, and if you see it, congratulation you server nginx has support CGI.

2. how to check CGI VULN

To diagnose the issue, temporarily install the following as a CGI script on your server and make it executable:

create file test.cgi

vi /var/www/html/cgi-bin/test.cgi

and this is the content, only insert it and save it.

#!/bin/sh
echo "Content-Type:text/plain"
​echo ""
echo "HTTP_PROXY='$HTTP_PROXY'"

Then call the CGI script with a “Proxy:” request header:

curl -H ‘Proxy: AFFECTED’ http://yourdefaultwebsite/cgi-bin/test.cgi

If you see the following output, your server is unaffected:

HTTP_PROXY=”

If instead you see the following, or any other output, your server may be affected and you should apply one of the mitigations below:

HTTP_PROXY=’AFFECTED’

Thank you, hop this can you 🙂

Reference :

1. A CGI Vulnerability https://httpoxy.org/
2. HTTPoxy – CGI “HTTP_PROXY” variable name clash, https://access.redhat.com/security/vulnerabilities/httpoxy
3. HTTPOXY Vulnerability: How to protect and test your web server, https://www.howtoforge.com/tutorial/httpoxy-protect-your-server/

 

 

Cara menambah size disk di debian

Mengalokasikan partisi disk tidak sesuai dengan kebutuhan memang merepotkan, dimana partisi dibuat sebesar 5GB ternyata kebutuhan lebih dari 5GB, maka solusinya adalah menambah size disk, sehingga partisi yang dialokasikan asalanya 5GB dapat diresize ke alokasi disk yg lebih besar lagi.

Tentunya dengan dapat mengextend disk mempermudah admin untuk tidak melakukan instalasi ulang untuk hanya menambah ukuran disk.

Dan berikut adalah video cara untuk exend disk :

 

 

Mengaktifkan Crontab di UBNT

Sabtu, 09 Juli 2016, widianto.org, mengaktifkan crontab di ubnt ini sengaja saya ingin aktifkan adalah untuk melakukan login secara otomatis pada jam tertentu. Di Rumahku terdapat wifi gratis yang mana pengaturannya adalah setiap pukul 18.00 wib secara otomatis semua koneksi di haruskan melakukan login ulang, dan ini cukup mengganggu apabila sedang melakukan download atau upload file pada jam-jam tersebut.

Maka solusinya adalah melakukan otomatis login pada jam tersebut, untuk konek ke wifi gratis tersebut saya menggunakan perangkat UBNT Nanostation M2 dengan Firmware Version: XM.v5.6.2. Untuk dapat UBNT melakukan login secara otomatis, perlu di aktifkan crontab di ubnt terlebih dahulu.

Apabila anda pernah coba utak-atik ubnt dengan menambahkan file konfigurasi di ubnt melalui console, anda pasti akan mengalami hal dimana setelah ditambahkan file konfigurasi tersebut setelah ubnt di reboot maka file konfigurasi tersebut akan hilang atau tidak tersimpan, begitupun dalam mengaktifkan cron di ubnt, ada cara khusus yg harus dilakukan agar file hasil konfigurasi tersebut tetap ada walau ubnt direboot, dan lakukan langkah seperti dibawah ini untuk mengaktifkan cron di ubnt.

SSH ke UBNT anda dan lakukan dibawah ini :

touch /etc/persistent/rc.poststart
chmod +x /etc/persistent/rc.poststart
vi /etc/persistent/rc.poststart

Input text berikut

#!/bin/sh
mkdir /etc/crontabs
/usr/bin/crond start
echo "1 18 * * * wget -O - http://hotspot.co/login?username=sudrun@widianto.org" >> /etc/crontabs/ubnt

kemudian agar file tidak hilang disaat ubnt di reboot lakukan perintah berikut :

cfgmtd -w -p /etc
reboot
Setelah reboot kemudian SSH kembali ubnt anda dan cek crontab yg telah di konfigurasi sebelumnya :
crontab -l
Dan sekarang anda dapat melihat seperti gambar dibawah ini :
widianto.org cron ubnt