Public Vulnerability Reports

Ipswitch Collaboration Suite SMTP Format String Vulnerability



Ipswitch Collaboration Suite provides e-mail and real-time
collaboration, calendar and contact list sharing, and protection from
spam and viruses, all delivered in an easy to use suite.


Remote exploitation of a format string vulnerability in Ipswitch
IMail allows remote attackers to execute arbitrary code.

The vulnerability specifically exists due to improper use of functions
which allow format specifiers in the SMTP service included with ICS.
Remote attackers can supply format string values to certain string
functions to cause memory corruption leading to remote code execution.
The vulnerability may be exploited by supplying specially crafted
strings to any of the following SMTP commands: EXPN, MAIL, MAIL FROM,
RCPT TO. All of the commands are handled by the same function which
parses user-supplied input strings. The following debugger session
shows a backtrace with user-supplied strings as values. With properly
constructed input value, the strings would be interpreted as memory
addresses that would be executed upon returning from the current

00A7F370   006020A0
00A7F374   00A7F634  ASCII 5B,"] MAIL
00A7F378   00000000
00A7F37C   00000000
00A7F380   7C34FC0B  RETURN to MSVCR71.7C34FC0B from MSVCR71.write_char
00A7F384   00602048
00A7F388   00A7F648  ASCII 20,"FROM:C:appsIpswitchCollaborat"


Successful exploitation of the format string vulnerability allows
unauthenticated remote attackers to execute arbitrary code. Ipswitch
mail services are commonly configured to allow untrusted access. The
use of a firewall or other mitigating strategy is highly recommended
due to the nature of this vulnerability. The IMail SMTP server is
installed by default.


iDEFENSE Labs has confirmed the existence of this vulnerability in
Ipswitch Collaboration Suite 8.20.


iDEFENSE is currently unaware of any effective workarounds for this
issue. Access to the affected host should be filtered at the network
boundary if global accessibility is not required. Restricting access to
only trusted hosts and networks may reduce the likelihood of


Ipswitch Collaboration Suite 2.02 has been released to address this
issue and is available for download at:

IMail Server 8.22  has been released to address this issue and is
available for download at:


The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2005-2931 to this issue. This is a candidate for inclusion in
the CVE list (, which standardizes names for
security problems.


09/08/2005   Initial vendor notification
09/13/2005   Initial vendor response
10/06/2005   Coordinated public disclosure


iDEFENSE credits Nico with the discovery of this vulnerability.

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Copyright © 2005 Verisign, Inc.

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Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
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