iDefense Security Advisory 06.16.10
http://labs.idefense.com/intelligence/vulnerabilities/
Jun 16, 2010

I. BACKGROUND

Samba is an open-source Unix server application used to implement
Windows file sharing and domain controlling functionality. For more
information, please visit: http://www.samba.org

II. DESCRIPTION

Remote exploitation of a buffer overflow vulnerability within Samba
Project's Samba could allow an attacker to execute arbitrary code with
root privileges.
This vulnerability exists in a certain function within Samba, where an
attacker could trigger a memory corruption by sending specially crafted
SMB requests resulting in heap memory overwritten with attacker supplied
data, which can allow attackers to execute code remotely.

III. ANALYSIS

Exploitation allows attackers to execute arbitrary code on the targeted
host with root privileges. To exploit this vulnerability, an attacker
would need to send a malicious SMB packet to a vulnerable Samba server.
It should be noted that this vulnerability works on samba default
configuration, no authentication is needed and no user action is
required. Unsuccessful exploitation attempts may cause the process
serving the request to crash and may leave evidence of an attack in
logs.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in Samba
version 3.3.12. Previous versions are suspected to be affected.Samba
3.4.0 and newer versions rewrite the whole logic of the vulnerable
function and thus are not affected by this vulnerability.

V. WORKAROUND

iDefense is currently unaware of any workaround for this issue.
Firewalls should be utilized to prevent unauthorized connections to
samba ports.

VI. VENDOR RESPONSE

Samba has released patches to address this issue. Information about
downloadable vendor updates can be found by clicking on the URL shown.
http://www.samba.org/samba/security/

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2010-2063 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

06/04/2010  Initial Vendor Notification
06/04/2010  Initial Vendor Reply
06/16/2010  Coordinated Public Disclosure

IX. CREDIT

This vulnerability was discovered by Jun Mao, iDefense Labs.

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X. LEGAL NOTICES

Copyright © 2010 iDefense, Inc.

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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.