‘CMail Vulnerable To a Buffer Overflow Attack (HELO)’


CMail Pop3 Mail Server enables every computer in your office to send and receive email not only across the Internet but also within your Local Area Network. A security vulnerability in the product allows remote attackers to overflow one of CMail’s internal buffers causing it to crash, and if a shellcode is provided in the overflowing buffer it may be possible to execute arbitrary code.’


‘The information has been provided by the SecuriTeam Experts.’


Vulnerable systems:
CMail version 2.4.9

Immune systems:
CMail version 2.4.10

By sending the following command:
HELO [buffer]

(Where [buffer] is a large string of over 484 characters), a remote attacker can crash the mail server remotely and possibly execute arbitrary code by overwriting the instruction pointer. This is true for every buffer larger than 484 characters, and smaller than 1000 characters.

Vendor status:
The following response was received from the vendor:
‘A fix has been implemented in the latest version of CMail Server (2.4.10) which is
scheduled for release to the public in the next week or so’

Categories: Windows