CVE-1999-0225: Windows NT 4.0 allows remote attackers to cause a denial of service via a malformed SMB logon reques
Windows NT 4.0 allows remote attackers to cause a denial of service via a malformed SMB logon request in which the actual data size does not match the specified size.
AI Analysis
Technical Summary
CVE-1999-0225 is a vulnerability affecting Microsoft Windows NT 4.0, specifically in the handling of Server Message Block (SMB) logon requests. The flaw arises when the system processes a malformed SMB logon request where the actual data size does not match the size specified in the request. This discrepancy can be exploited by remote attackers to cause a denial of service (DoS) condition, effectively crashing or destabilizing the affected system. The vulnerability does not require authentication and can be triggered remotely over the network, making it accessible to attackers without prior access. The impact is limited to availability, as the exploit causes service disruption but does not compromise confidentiality or integrity. The vulnerability was published in early 1998 and affects Windows NT 4.0, an operating system that is now obsolete and unsupported. No patches or fixes are available for this vulnerability, and there are no known exploits actively used in the wild. The CVSS v2 score is 5.0 (medium severity), reflecting the ease of exploitation and the limited impact scope.
Potential Impact
For European organizations, the direct impact of CVE-1999-0225 is minimal in modern contexts due to the obsolescence of Windows NT 4.0. However, any legacy systems still running this OS could be vulnerable to remote denial of service attacks, potentially disrupting critical services relying on SMB communication. Such disruption could affect internal network operations, file sharing, and authentication services that depend on SMB. While confidentiality and integrity are not at risk, availability interruptions can cause operational delays and loss of productivity. Organizations in sectors with legacy infrastructure, such as industrial control systems, manufacturing, or government agencies with older IT environments, might face higher risks. Additionally, denial of service attacks could be leveraged as part of multi-stage attacks or to create distractions for other malicious activities.
Mitigation Recommendations
Given the absence of patches, the primary mitigation is to phase out Windows NT 4.0 systems and migrate to supported, modern operating systems that receive security updates. For environments where legacy systems must remain operational, network-level protections should be implemented: restrict SMB traffic using firewalls and network segmentation to limit exposure to untrusted networks; employ intrusion detection/prevention systems (IDS/IPS) to monitor and block malformed SMB packets; disable SMB services on Windows NT 4.0 machines if not essential; and use virtual private networks (VPNs) or other secure tunnels to protect SMB traffic when remote access is necessary. Regular network monitoring and anomaly detection can help identify attempts to exploit this vulnerability. Additionally, organizations should maintain an asset inventory to identify any remaining Windows NT 4.0 systems and prioritize their replacement or isolation.
Affected Countries
Germany, France, United Kingdom, Italy, Spain, Poland, Netherlands
CVE-1999-0225: Windows NT 4.0 allows remote attackers to cause a denial of service via a malformed SMB logon reques
Description
Windows NT 4.0 allows remote attackers to cause a denial of service via a malformed SMB logon request in which the actual data size does not match the specified size.
AI-Powered Analysis
Technical Analysis
CVE-1999-0225 is a vulnerability affecting Microsoft Windows NT 4.0, specifically in the handling of Server Message Block (SMB) logon requests. The flaw arises when the system processes a malformed SMB logon request where the actual data size does not match the size specified in the request. This discrepancy can be exploited by remote attackers to cause a denial of service (DoS) condition, effectively crashing or destabilizing the affected system. The vulnerability does not require authentication and can be triggered remotely over the network, making it accessible to attackers without prior access. The impact is limited to availability, as the exploit causes service disruption but does not compromise confidentiality or integrity. The vulnerability was published in early 1998 and affects Windows NT 4.0, an operating system that is now obsolete and unsupported. No patches or fixes are available for this vulnerability, and there are no known exploits actively used in the wild. The CVSS v2 score is 5.0 (medium severity), reflecting the ease of exploitation and the limited impact scope.
Potential Impact
For European organizations, the direct impact of CVE-1999-0225 is minimal in modern contexts due to the obsolescence of Windows NT 4.0. However, any legacy systems still running this OS could be vulnerable to remote denial of service attacks, potentially disrupting critical services relying on SMB communication. Such disruption could affect internal network operations, file sharing, and authentication services that depend on SMB. While confidentiality and integrity are not at risk, availability interruptions can cause operational delays and loss of productivity. Organizations in sectors with legacy infrastructure, such as industrial control systems, manufacturing, or government agencies with older IT environments, might face higher risks. Additionally, denial of service attacks could be leveraged as part of multi-stage attacks or to create distractions for other malicious activities.
Mitigation Recommendations
Given the absence of patches, the primary mitigation is to phase out Windows NT 4.0 systems and migrate to supported, modern operating systems that receive security updates. For environments where legacy systems must remain operational, network-level protections should be implemented: restrict SMB traffic using firewalls and network segmentation to limit exposure to untrusted networks; employ intrusion detection/prevention systems (IDS/IPS) to monitor and block malformed SMB packets; disable SMB services on Windows NT 4.0 machines if not essential; and use virtual private networks (VPNs) or other secure tunnels to protect SMB traffic when remote access is necessary. Regular network monitoring and anomaly detection can help identify attempts to exploit this vulnerability. Additionally, organizations should maintain an asset inventory to identify any remaining Windows NT 4.0 systems and prioritize their replacement or isolation.
Affected Countries
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Threat ID: 682ca32bb6fd31d6ed7de8fe
Added to database: 5/20/2025, 3:43:39 PM
Last enriched: 7/1/2025, 10:40:36 PM
Last updated: 8/11/2025, 12:02:22 AM
Views: 11
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