SECURITY.NNOV URL: http://www.security.nnov.ru/advisories
Topic: The Bat! <cr> bug
Application: The Bat! 1.51 (latest)
Category: Denial of Service
Risk Factor: Low
Vendor Contacted: 13.04.2001
Software URL: http://www.thebat.net
Vendor URL: http://www.ritlabs.com
The Bat! Is very convenient commercially available MUA for Windows
with lot of features.
While RETRiving message via POP3 (IMAP isn't tested) The Bat!
incorrectly processes 0x0D (CR) character if it's not followed by
0x0A (LF). Probably each 0x0D character is treated as 2 octets and
The Bat! incorrectly calculates size of the message and the part of
message is treated as reply from POP3 server. The Bat! fails to
receive the rest of the messages and fails to delete received
messages from server. This leads to DoS against user's POP3 account.
Malformed message can emulate any POP3 server replies.
Extract attached "badmessage" and send it, e.g. using
cat badmessage | sendmail -U email@example.com
or copy it to user's mailbox.
This message causes The Bat! to show something like:
!13.04.2001, 17:51:01: FETCH - Server reports error. The response is:
--ERR Wrong User: replace user with your system administrator--
use "Dispatch Mail on Server" feature to delete malformed message
from server or use different MUA.
Install TheBat! >= 1.52
RitLabs was contacted on April, 13 (happy Easter to you, guys). No
This advisory is being provided to you under RFPolicy v.2 documented