CVE-2003-0661 in Windows
Summary
by MITRE
The NetBT Name Service (NBNS) for NetBIOS in Windows NT 4.0, 2000, XP, and Server 2003 may include random memory in a response to a NBNS query, which could allow remote attackers to obtain sensitive information.
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Analysis
by VulDB Data Team • 12/31/2024
The vulnerability described in CVE-2003-0661 represents a critical information disclosure flaw within the NetBIOS Name Service implementation across multiple Windows operating systems including Windows NT 4.0, 2000, XP, and Server 2003. This issue specifically affects the NetBT Name Service component that handles NetBIOS Name Service queries, which are fundamental to Windows network communication and name resolution. The flaw manifests when the system responds to NBNS queries by inadvertently including random memory values from the system's memory space within the response packets, potentially exposing sensitive data that could be valuable to attackers.
The technical nature of this vulnerability stems from improper memory handling within the NetBIOS Name Service implementation where the system fails to properly clear or initialize memory buffers before including them in response packets. When a remote attacker sends a NBNS query to a vulnerable Windows system, the response may contain uninitialized memory segments that could include fragments of sensitive information such as passwords, session keys, or other confidential data that was previously stored in the memory locations. This occurs because the name service does not properly sanitize the memory content before sending it back in response to the query, creating an information disclosure channel that can be exploited by remote adversaries.
The operational impact of this vulnerability is significant as it provides attackers with a method to perform passive information gathering without requiring any authentication or active exploitation. Attackers can leverage this flaw to conduct reconnaissance activities, potentially obtaining credentials, session information, or other sensitive data that could be used for further attacks. The vulnerability is particularly concerning because it operates at the network level and can be exploited remotely, making it accessible to anyone who can send NBNS queries to the target system. This information disclosure could enable attackers to escalate privileges, conduct man-in-the-middle attacks, or gain deeper insights into the target network infrastructure and systems.
Security professionals should implement immediate mitigations including network segmentation to isolate vulnerable systems, disabling NBNS where possible, and applying appropriate firewall rules to restrict NBNS traffic. The vulnerability aligns with CWE-200, which addresses "Information Exposure," and represents a classic example of how improper memory handling can lead to information disclosure. From an ATT&CK perspective, this vulnerability maps to techniques involving reconnaissance and credential access, as it enables attackers to gather sensitive information that could be used for privilege escalation or lateral movement within a network. Organizations should also consider implementing network monitoring to detect unusual NBNS query patterns and ensure that systems are updated with appropriate security patches to address this memory handling flaw in the NetBIOS Name Service implementation.