[Full-Disclosure] iDEFENSE Security Advisory 09.13.04b: Samba 3.x SMBD Remote Denial of Service Vulnerability

2004-09-14T00:00:00
ID SECURITYVULNS:DOC:6792
Type securityvulns
Reporter Securityvulns
Modified 2004-09-14T00:00:00

Description

Samba 3.x SMBD Remote Denial of Service Vulnerability

iDEFENSE Security Advisory 09.13.04b www.idefense.com/application/poi/display?id=139&type=vulnerabilities September 13, 2004

I. BACKGROUND

Samba is a software suite that provides file and print services to SMB/CIFS clients, such as Microsoft Windows platforms. For more information see:

http://www.samba.org/

II. DESCRIPTION

An unauthenticated remote user can cause a resource exhaustion attack by sending multiple malformed requests to an affected server. Each request spawns a new process, which enters an infinite loop.

III. ANALYSIS

This attack takes very little bandwidth to cause the machine to stop responding. Each request from the exploit tested was only 358 bytes, and a Redhat Fedora Core 1 machine with 512 megabytes of RAM and 512 megabytes of swap took fewer than 4000 requests to render it unusable.

IV. DETECTION

iDEFENSE has confirmed Samba 3.0.2 and 3.0.4 are vulnerable.

The vendor has confirmed that Samba 3.0.x prior to and including v3.0.6 are vulnerable.

V. WORKAROUND

Restricting access to the server by using the "hosts allow" setting in smb.conf and/or applying firewall rules may help mitigate this vulnerability.

VI. VENDOR RESPONSE

The patch file for Samba 3.0.5 addressing [the] bug (samba-3.0.5-DoS.patch) can be downloaded from:

http://download.samba.org/samba/ftp/patches/security/

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the names CAN-2004-0807 to these issues. This is a candidate for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems.

VIII. DISCLOSURE TIMELINE

09/02/2004 Initial vendor notification 09/02/2004 iDEFENSE clients notified 09/02/2004 Vendor response 09/13/2004 Coordinated public disclosure

IX. CREDIT

The discoverer wishes to remain anonymous.

Get paid for vulnerability research http://www.idefense.com/poi/teams/vcp.jsp

X. LEGAL NOTICES

Copyright (c) 2004 iDEFENSE, Inc.

Permission is granted for the redistribution of this alert electronically. It may not be edited in any way without the express written consent of iDEFENSE. If you wish to reprint the whole or any part of this alert in any other medium other than electronically, please email customerservice@idefense.com for permission.

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.


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