CVE-2021-28442 in Windows
Summary
by MITRE • 04/14/2021
Windows TCP/IP Information Disclosure Vulnerability
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Analysis
by VulDB Data Team • 04/16/2021
The Windows TCP/IP Information Disclosure Vulnerability CVE-2021-28442 represents a critical security flaw in the Windows operating system's network stack that allows attackers to potentially extract sensitive information from affected systems. This vulnerability specifically impacts the Transmission Control Protocol/Internet Protocol implementation within Windows, creating an information disclosure channel that could be exploited by remote attackers without authentication. The flaw exists in the way Windows handles certain TCP/IP network communications and can potentially reveal internal network information, system details, or configuration data that should remain confidential. According to the vulnerability classification, this issue falls under the category of information disclosure vulnerabilities, which are particularly dangerous as they can provide attackers with insights that facilitate more sophisticated attacks. The vulnerability affects multiple Windows versions including Windows 10, Windows Server 2016, and Windows Server 2019, making it a widespread concern across enterprise environments.
The technical implementation of this vulnerability stems from improper handling of TCP/IP network packets within the Windows kernel network driver components. When processing specific network traffic patterns, the system fails to properly validate or sanitize certain packet headers or payload data, leading to information leakage through network responses. This type of flaw typically manifests when the system generates network responses that inadvertently include internal memory contents, system identifiers, or configuration parameters that should not be exposed to external network entities. The vulnerability can be triggered through normal network communication patterns, making it particularly insidious as it may not require specific malicious actions from the attacker beyond establishing network connectivity to the affected system. The root cause aligns with CWE-200, which describes improper handling of sensitive information, and represents a classic case of information exposure through network protocols where security boundaries are not properly maintained during packet processing operations.
The operational impact of CVE-2021-28442 extends beyond simple information disclosure, as the leaked data can significantly aid attackers in planning more targeted attacks against the compromised systems. Network information that may be exposed includes internal IP addressing schemes, system configuration details, and potentially even memory layout information that could be used for further exploitation attempts. This vulnerability creates a reconnaissance opportunity for threat actors to gather intelligence about network topology, system configurations, and potential security weaknesses within the affected infrastructure. Organizations running affected Windows systems may experience increased risk of subsequent attacks including privilege escalation, lateral movement, or more sophisticated exploitation techniques that leverage the additional information gained through this vulnerability. The impact is particularly severe in enterprise environments where network segmentation and security controls are already in place, as this vulnerability can potentially bypass some of the expected security boundaries by revealing internal network details that should remain hidden from external entities.
Mitigation strategies for CVE-2021-28442 should focus on immediate patch deployment through Microsoft's regular security updates, which address the core TCP/IP processing flaw in the Windows kernel network components. Organizations should prioritize patching across all affected Windows versions including Windows 10, Windows Server 2016, and Windows Server 2019, implementing the security updates as soon as they become available. Network administrators should also consider implementing additional monitoring and detection measures to identify potential exploitation attempts, including reviewing network logs for unusual packet patterns or information disclosure attempts. The vulnerability's classification under ATT&CK technique T1082, which covers system information discovery, indicates that this flaw could be leveraged as part of broader reconnaissance activities. Organizations should also review their network segmentation policies and ensure that internal network information is properly protected even when exposed through legitimate network protocols. Network firewalls and intrusion detection systems should be configured to monitor for unusual information disclosure patterns, and security teams should conduct thorough vulnerability assessments to identify any potential exploitation attempts that may have occurred prior to patch deployment.