Mikhail pirenga

## proxmox-proxy
I ran into the battle of running all of my VMs and the host node under a single public IP address. Luckily, the host is just pure Debian, and ships with iptables.

What needs to be done is essentially to run all the VMs on a private internal network. Outbound internet access is done via NAT. Inbound access is via port forwarding.

Network configuration

Here’s how it’s done:

Create a virtual interface that serves as the gateway for your VMs:

## Rconfig File Upload RCE Exploit
Remote Code Execution via File Upload (CVE-2020-12255)


The rConfig 3.9.4 is vulnerable to remote code execution due to improper checks/validation via the file upload functionality.
The vendor.crud.php accepts the file upload by checking through content-type and it is not restricting upload by checking the file extension and header.
Due to this flaw, An attacker can exploit this vulnerability by uploading a PHP file that contains arbitrary code (shell) and changing the content-type to `image/gif` in the vendor.crud.php.
since the validation checks are happening through content-type the server would accept the PHP file uploaded ultimately resulting code execution upon the response when invoked.


Steps To Reproduce-:

## recaptcha-example-js.html
<!--
Description: The following is the example code to use recaptcha.
Notice: The function backend_API_challenge is the concept and you should implement it on the backend.
        Especially, you must keep your secret key in private all the time.
Flow:
1. Click the submit button.
2. On the console, execute backend_API_challenge function.
-->
<html>
<head>

## trim.awk
function ltrim(s) { sub(/^[ \t\r\n]+/, "", s); return s }
function rtrim(s) { sub(/[ \t\r\n]+$/, "", s); return s }
function trim(s)  { return rtrim(ltrim(s)); }
BEGIN {
# whatever
}
{
# whatever
}
END {

## Ansible Let's Encrypt Nginx setup
Ansible playbook to setup HTTPS using Let's encrypt on nginx.

The Ansible playbook installs everything needed to serve static files from a nginx server over HTTPS.
The server pass A rating on [SSL Labs](https://www.ssllabs.com/).

To use:
 1. Install [Ansible](https://www.ansible.com/)
 2. Setup an Ubuntu 16.04 server accessible over ssh
 3. Create `/etc/ansible/hosts` according to template below and change example.com to your domain
 4. Copy the rest of the files to an empty directory (`playbook.yml` in the root of that folder and the rest in the `templates` subfolder)

## gist:6a7fdfd463cfe2d660ba5cb04f20121e
/ipv6 firewall filter
add action=accept chain=input comment="Allow established connections" connection-state=established disabled=no
add action=accept chain=input comment="Allow related connections" connection-state=related disabled=no
add action=accept chain=input comment="Allow limited ICMP" disabled=no limit=50/5s,5 protocol=icmpv6
add action=accept chain=input comment="Allow UDP" disabled=no protocol=udp
add action=drop chain=input comment="" disabled=no
add action=accept chain=forward comment="Allow any to internet" disabled=no out-interface=sit1
add action=accept chain=forward comment="Allow established connections" connection-state=established disabled=no
add action=accept chain=forward comment="Allow related connections" connection-state=related disabled=no
add action=drop chain=forward comment="" disabled=no

## gist:1df556f7e4885f8b3273db8b304d0d5e
18   ;;; 7/0 goes to WAN1
     chain=prerouting action=mark-connection new-connection-mark=WAN1_conn passthrough=yes
     dst-address-type=!local in-interface=LAN1 connection-mark=no-mark
     per-connection-classifier=both-addresses-and-ports:7/0

19   ;;; 7/1 goes to WAN2
     chain=prerouting action=mark-connection new-connection-mark=WAN2_conn passthrough=yes
     dst-address-type=!local in-interface=LAN1 connection-mark=no-mark
     per-connection-classifier=both-addresses-and-ports:7/1
	I ran into the battle of running all of my VMs and the host node under a single public IP address. Luckily, the host is just pure Debian, and ships with iptables.

	What needs to be done is essentially to run all the VMs on a private internal network. Outbound internet access is done via NAT. Inbound access is via port forwarding.

	Network configuration

	Here’s how it’s done:

	Create a virtual interface that serves as the gateway for your VMs:
	Remote Code Execution via File Upload (CVE-2020-12255)


	The rConfig 3.9.4 is vulnerable to remote code execution due to improper checks/validation via the file upload functionality.
	The vendor.crud.php accepts the file upload by checking through content-type and it is not restricting upload by checking the file extension and header.
	Due to this flaw, An attacker can exploit this vulnerability by uploading a PHP file that contains arbitrary code (shell) and changing the content-type to `image/gif` in the vendor.crud.php.
	since the validation checks are happening through content-type the server would accept the PHP file uploaded ultimately resulting code execution upon the response when invoked.


	Steps To Reproduce-:
	<!--
	Description: The following is the example code to use recaptcha.
	Notice: The function backend_API_challenge is the concept and you should implement it on the backend.
	Especially, you must keep your secret key in private all the time.
	Flow:
	1. Click the submit button.
	2. On the console, execute backend_API_challenge function.
	-->
	<html>
	<head>
	function ltrim(s) { sub(/^[ \t\r\n]+/, "", s); return s }
	function rtrim(s) { sub(/[ \t\r\n]+$/, "", s); return s }
	function trim(s) { return rtrim(ltrim(s)); }
	BEGIN {
	# whatever
	}
	{
	# whatever
	}
	END {
	Ansible playbook to setup HTTPS using Let's encrypt on nginx.

	The Ansible playbook installs everything needed to serve static files from a nginx server over HTTPS.
	The server pass A rating on [SSL Labs](https://www.ssllabs.com/).

	To use:
	1. Install [Ansible](https://www.ansible.com/)
	2. Setup an Ubuntu 16.04 server accessible over ssh
	3. Create `/etc/ansible/hosts` according to template below and change example.com to your domain
	4. Copy the rest of the files to an empty directory (`playbook.yml` in the root of that folder and the rest in the `templates` subfolder)
	/ipv6 firewall filter
	add action=accept chain=input comment="Allow established connections" connection-state=established disabled=no
	add action=accept chain=input comment="Allow related connections" connection-state=related disabled=no
	add action=accept chain=input comment="Allow limited ICMP" disabled=no limit=50/5s,5 protocol=icmpv6
	add action=accept chain=input comment="Allow UDP" disabled=no protocol=udp
	add action=drop chain=input comment="" disabled=no
	add action=accept chain=forward comment="Allow any to internet" disabled=no out-interface=sit1
	add action=accept chain=forward comment="Allow established connections" connection-state=established disabled=no
	add action=accept chain=forward comment="Allow related connections" connection-state=related disabled=no
	add action=drop chain=forward comment="" disabled=no
	18 ;;; 7/0 goes to WAN1
	chain=prerouting action=mark-connection new-connection-mark=WAN1_conn passthrough=yes
	dst-address-type=!local in-interface=LAN1 connection-mark=no-mark
	per-connection-classifier=both-addresses-and-ports:7/0

	19 ;;; 7/1 goes to WAN2
	chain=prerouting action=mark-connection new-connection-mark=WAN2_conn passthrough=yes
	dst-address-type=!local in-interface=LAN1 connection-mark=no-mark
	per-connection-classifier=both-addresses-and-ports:7/1