From labs-no-reply@idefense.com Tue May 24 17:25:59 2005 From: iDEFENSE Labs To: bugtraq@securityfocus.com, vulnwatch@vulnwatch.org, full-disclosure@lists.grok.org.uk Date: Tue, 24 May 2005 16:09:20 -0400 Subject: iDEFENSE Security Advisory 05.24.05: Ipswitch IMail IMAP LOGIN Remote Buffer Overflow Vulnerabilities Ipswitch IMail IMAP LOGIN Remote Buffer Overflow Vulnerabilities iDEFENSE Security Advisory 05.24.05 www.idefense.com/application/poi/display?id=243&type=vulnerabilities May 24, 2005 I. BACKGROUND Ipswitch Collaboration Suite (ICS) is a comprehensive communication and collaboration solution for Microsoft Windows with a customer base of over 53 million users. More information is available on the vendor's website: http://www.ipswitch.com/products/IMail_Server/index.html II. DESCRIPTION Remote exploitation of several buffer overflow vulnerabilities in Ipswitch Inc.'s Imail IMAP server allows attackers to execute arbitrary code with System privileges. The first vulnerability specifically exists in the handling of a long username to the LOGIN command. A long username argument of approximately 2,000 bytes will cause a stack based unicode string buffer overflow providing the attacker with partial control over EIP. As this vulnerability is in the LOGIN command itself, valid credentials are not required. The second vulnerability also exists in the handling of the LOGIN command username argument, however it lends itself to easier exploitation. If a large username starting with one of several special characters is specified, a stack overflow occurs, allowing an attacker to overwrite the saved instruction pointer and control execution flow. Included in the list of special characters are the following: % : * @ & Both of these vulnerabilities can lead to the execution of arbitrary code. III. ANALYSIS Successful exploitation allows remote attackers to execute arbitrary code with System privileges. Valid credentials are not required to for exploitation, which heightens the impact of this vulnerability. IV. DETECTION iDEFENSE has confirmed the existence of this vulnerability in the latest version of Ipswitch IMAIL, version 8.13. Version 8.12 is also confirmed as vulnerable. It is suspected that earlier versions are also vulnerable. V. WORKAROUND As this vulnerability is exploited before authentication occurs, the only effective workaround is to limit access to the IMAP server by filtering TCP port 143. If possible, consider disabling IMAP and forcing users to use POP3. VI. VENDOR RESPONSE The vendor has released the following patch to fix this vulnerability: ftp://ftp.ipswitch.com/Ipswitch/Product_Support/IMail/imail82hf2.exe The associated vendor advisory can be found at: http://www.ipswitch.com/support/imail/releases/imail_professional/im82hf 2.html VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the name CAN-2005-1255 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems. VIII. DISCLOSURE TIMELINE 04/25/2005 Initial vendor notification 05/10/2005 Initial vendor response 05/24/2005 Public disclosure IX. CREDIT The discoverer of the first vulnerability wishes to remain anonymous. iDEFENSE Labs is credited with the discovery of the second vulnerability. Get paid for vulnerability research http://www.idefense.com/poi/teams/vcp.jsp Free tools, research and upcoming events http://labs.idefense.com X. LEGAL NOTICES Copyright (c) 2005 iDEFENSE, Inc. Permission is granted for the redistribution of this alert electronically. It may not be edited in any way without the express written consent of iDEFENSE. If you wish to reprint the whole or any part of this alert in any other medium other than electronically, please email customerservice@idefense.com for permission. Disclaimer: The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.