Qualys has discovered a vulnerability in certain versions of Microsoft Windows, which can be exploited by malicious people to cause a DoS (Denial of Service) and potentially compromise a vulnerable system.

The vulnerability is caused due to a boundary error in WINS (Windows Internet Naming Service) when validating the length of certain packets. This can be exploited to cause a buffer overflow by sending a series of specially crafted packets to a vulnerable WINS server.

Successful exploitation will likely result in the WINS service being terminated on Windows Server 2003 due to a security feature, which detects stack-based buffer overflows. However, arbitrary code execution may potentially still be possible.

According to Microsoft, the nature of the vulnerability is different on Windows NT and 2000. The malicious packets are rejected by the WINS service and can therefore not be exploited to cause a DoS or execute code. However, Microsoft has still released patches for these versions as a preventive measure.

Solution
Apply patch.
Further details available in Customer Area

Provided and/or discovered by
Qualys

Changelog
Further details available in Customer Area

Original Advisory
MS04-006:
http://www.microsoft.com/technet/security/bulletin/MS04-006.asp

Qualys:
http://www.qualys.com/docs/securityalerts/Qadvise-Microsoft-WINS-20040210.pdf

Other references
Further details available in Customer Area

Deep Links
Links available in Customer Area