LeapFTP .lsq Buffer Overflow Vulnerability

by Sowhat

Last Update:2005.08.24

http://secway.org/advisory/AD20050824.txt

Vendor:

LeapWare Inc.

Product Affected:

LeapFTP < 2.7.6.612

Overview:

LeapFTP is the award-winning shareware FTP client that combines an 
intuitive interface with one of the most powerful client bases around. 


Details:

.LSQ is the LeapFTP Site Queue file, And it is registered with Windows
by LeapFTP. You can save a transfer Queue to .lsq files and transfer it
later by opening the .lsq files. 

However, LeapFTP does not properly check the length of the "Host" fields,
when a overly long string is supplied, there will be a buffer overflow
and probably arbitrary code execution.

This vulnerability can be exploited by sending the malformed .lsq file
to the victim, after the victim open the .lsq file, arbitray code may
executed.


//bof.lsq

[HOSTINFO]
HOST=AAAAA...[ long string ]...AAAAA
USER=username
PASS=password

[FILES]
"1","/winis/ApiList.zip","477,839","E:\ApiList.zip"

SOLUTION:

All users are encouraged to upgrade to 2.7.6 immediately
Vendor also released an advisory:
http://www.leapware.com/security/2005082301.txt

Vendor Response:

2005.08.22 Vendor notified via online WebForm 
2005.08.23 Vendor responsed and bug fixed
2005.08.24 Vendor released the new version 2.7.6.612
2005.08.24 Advisory Released