Samba Input Validation Error in ms_fnmatch() Lets Remote Authenticated Users Deny Service
SecurityTracker Alert ID: 1012133|
SecurityTracker URL: http://securitytracker.com/id/1012133
(Links to External Site)
Updated: Oct 18 2006|
Original Entry Date: Nov 8 2004
Denial of service via network|
Fix Available: Yes Vendor Confirmed: Yes Exploit Included: Yes |
Version(s): 3.0 through 3.0.7|
An input vulnerability was reported in Samba. A remote authenticated user may be able to cause denial of service conditions.|
The vendor reported that there is a flaw in the matching of filenames containing wildcard characters. A remote user can cause the target smbd process to consume excessive CPU resources and, in some cases, cause the system to stop responding.
The vendor credits iDEFENSE with reporting this flaw.
iDEFENSE reported that the flaw resides in the ms_fnmatch() function and can be triggered by sending a command that contains multiple asterik characters, such as the following command:
A remote authenticated user can cause excessive CPU consumption on the target system, potentially causing the system to become unresponsive.|
A patch for Samba 3.0.7 (samba-3.0.7-CAN-2004-0930.patch) is available at:|
The patch has been signed with the "Samba Distribution Verification Key" (ID F17F9772).
Vendor URL: www.samba.org/ (Links to External Site)
Input validation error, State error|
|Underlying OS: Linux (Any), UNIX (Any)|
This archive entry has one or more follow-up message(s) listed below.|
Source Message Contents
Date: Mon, 08 Nov 2004 11:45:02 -0600|
Subject: [SECURITY] CAN-2004-0930: Potential Remote Denial of Service Vulnerability
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Subject: Potential Remote Denial of Service
CVE #: CAN-2004-0930
Versions: Samba 3.0.x <= 3.0.7
Summary: A remote attacker could cause and smbd process
to consume abnormal amounts of system resources
due to an input validation error when matching
filenames containing wildcard characters.
A patch for Samba 3.0.7 (samba-3.0.7-CAN-2004-0930.patch) is
available from http://www.samba.org/samba/ftp/patches/security/.
The patch has been signed with the "Samba Distribution Verification
Key" (ID F17F9772).
A bug in the input validation routines used to match
filename strings containing wildcard characters may allow
a user to consume more than normal amounts of CPU cycles
thus impacting the performance and response of the server.
In some circumstances the server can become entirely
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
This security issue was reported to Samba developers by
iDEFENSE (http://www.idefense.com/). Karol Wiesek is credited
with this discovery.
Our Code, Our Bugs, Our Responsibility.
-- The Samba Team
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