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NSFOCUS Security Advisory(SA2003-01)

Topic: Microsoft Windows XP Redirector Local Buffer Overflow Vulnerability

Release Date: 2003-3-27

CVE CAN ID: CAN-2003-0004

Affected system:

• • Microsoft Windows XP
• • Microsoft Windows XP SP1

Summary:

NSFOCUS Security Team has found a buffer overflow vulnerability in Microsoft
Windows XP Redirector. Exploiting the vulnerability local attackers
could crash the system or gain local system privilege by carefully crafted
code.

Description:

The Windows Redirector is used to access files, whether local or remote.It
is used to access network shares by net use command.

A security vulnerability exists in the Windows Redirector on Windows XP.An
unchecked length in handling the received parameter information causes a
buffer overflow vulnerability. Exploiting the vulnerability a non-privileged
user could cause system blue screen and reboot. If the code was carefully
crafted, attackers could execute arbitrary command in system privilege. At
present no remote exploitation method has been found.

Only Windows XP is vulnerable to the issue. Windows NT 4.0, Windows NT 4.0
Terminal Server Edition, and Windows 2000 do not contain the vulnerable code
and are not affected by this vulnerability.

Exploit:

Enter the following command as a non-privileged user in the command line
window:

c:\> net use \\AAAA…AAA[about 1000-2000 'A' characters]\A

Windows XP will become blue screen or reboot immediately.

Note: Attackers have to be able to login interactively.

Workaround:

Prohibit untrusted user login to your system.

Vendor Status:

Microsoft has issued a Security Bulletin(MS03-005) and the related patch.

Detailed Microsoft Security Bulletin is available at:

http://www.microsoft.com/technet/security/bulletin/ms03-005.asp

Patches are available at:

. Microsoft Windows XP 32-bit Edition:
http://microsoft.com/downloads/details.aspx?FamilyId=33DABD1F-505E-48ED-B9BD-CDAC0F8A2BC1

. Microsoft Windows XP 64-bit Edition:
http://microsoft.com/downloads/details.aspx?FamilyId=A2258F4E-9A69-4537-9469-0DDEB4BB76F8

Additional Information:

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2003-0004 to this issue. This is a candidate for inclusion in the
CVE list (http://cve.mitre.org), which standardizes names for security
problems. Candidates may change significantly before they become official
CVE entries.

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Copyright 1999-2003 NSFOCUS. All Rights Reserved. Terms of use.

NSFOCUS Security Team <[email protected]>
NSFOCUS INFORMATION TECHNOLOGY CO.,LTD
(http://www.nsfocus.com)

PGP Key: http://www.nsfocus.com/homepage/research/pgpkey.asc
Key fingerprint = F8F2 F5D1 EF74 E08C 02FE 1B90 D7BF 7877 C6A6 F6DA
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