Samba 3.0 DoS Vulnerabilities (CAN-2004-0807 & CAN-2004-0808)
Gerald (Jerry) Carter
jerry at samba.org
Mon Sep 13 11:58:24 GMT 2004
-----BEGIN PGP SIGNED MESSAGE-----
Subject: Samba 3.0.x Denial of Service Flaw
Summary: (i) A DoS bug in smbd may allow an
unauthenticated user to cause smbd to
spawn new processes each one entering
an infinite loop. After sending a sufficient
amount of packets it is possible to exhaust
the memory resources on the server.
(ii) A DoS bug in nmbd may allow an attacker
to remotely crash the nmbd daemon.
Versions: Defect (i) affects Samba 3.0.x prior to and
Defect (ii) affects Samba 3.0.x prior to
and including v3.0.6.
Availability: The patch file for Samba 3.0.5 addressing both
bugs (samba-3.0.5-DoS.patch) can be downloaded
CAN-2004-0807: A defect in smbd's ASN.1 parsing allows an
attacker to send a specially crafted packet during the
authentication request which will send the newly spawned
smbd process into an infinite loop. Given enough of these
packets, it is possible to exhaust the available memory
on the server.
CAN-2004-0808: A defect in nmbd's process of mailslot packets
can allow an attacker to anonymously crash nmbd.
Protecting Unpatched Servers
The Samba Team always encourages users to run the latest stable
release as a defense of against attacks. However, under certain
circumstances it may not be possible to immediately upgrade
important installations. In such cases, administrators should
read the "Server Security" documentation found at
Both security issues were reported to Samba developers by
iDEFENSE (http://www.idefense.com/). The defect discovery
was anonymously reported to iDEFENSE via their Vulnerability
Contributor Program (http://www.idefense.com/poi/teams/vcp.jsp).
Our Code, Our Bugs, Our Responsibility.
-- The Samba Team
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
-----END PGP SIGNATURE-----
More information about the samba-technical