CVE-2013-3876 in Windows
Summary
by MITRE
DirectAccess in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP1 and SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1 does not properly verify server X.509 certificates, which allows man-in-the-middle attackers to spoof servers and read encrypted domain credentials via a crafted certificate.
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Analysis
by VulDB Data Team • 12/25/2024
The vulnerability identified as CVE-2013-3876 represents a critical certificate validation flaw within Microsoft Windows DirectAccess implementations across multiple operating system versions. This security weakness specifically targets the X.509 certificate verification process that occurs during DirectAccess server authentication, creating a pathway for sophisticated man-in-the-middle attacks. The flaw exists in Windows versions ranging from XP SP2 through Windows 8.1 and their respective server editions, indicating a widespread impact that affects enterprise environments relying on DirectAccess for secure remote connectivity. The vulnerability stems from insufficient certificate validation mechanisms that fail to properly verify the authenticity and trustworthiness of server certificates presented during the DirectAccess handshake process.
The technical exploitation of this vulnerability allows attackers to craft malicious X.509 certificates that can successfully bypass the normal certificate validation procedures implemented by DirectAccess. This weakness specifically affects the certificate chain validation process where the client system should verify that the server certificate is issued by a trusted certificate authority and properly matches the target server. Attackers can leverage this flaw to present forged certificates that appear legitimate to the client system, enabling them to intercept and decrypt domain credentials transmitted through the DirectAccess connection. The attack vector requires the attacker to be in a position to intercept network traffic between the client and server, typically within the same network segment or through network position that allows traffic interception.
The operational impact of this vulnerability extends beyond simple credential theft, as it compromises the fundamental security model of DirectAccess implementations. When exploited successfully, attackers can gain access to encrypted domain credentials that may include administrative privileges, potentially leading to complete network compromise. The vulnerability affects organizations that deploy DirectAccess for secure remote access, as it undermines the trust model that DirectAccess relies upon for establishing secure connections. This weakness particularly impacts enterprise environments where DirectAccess is used to provide seamless secure access to internal network resources from remote locations, creating a significant risk for organizations that depend on this technology for remote worker connectivity and branch office access.
Organizations should implement immediate mitigations including applying Microsoft security updates that address the certificate validation flaw, disabling DirectAccess functionality where possible, and implementing additional network monitoring to detect potential exploitation attempts. The vulnerability aligns with CWE-295 which addresses improper certificate validation and relates to ATT&CK technique T1552.001 for credentials from password storage. Network administrators should consider implementing certificate pinning mechanisms, enhanced certificate monitoring, and regular security assessments of DirectAccess configurations. The flaw demonstrates the importance of robust certificate validation in secure communication protocols and highlights the necessity of proper cryptographic implementation in enterprise security solutions. Organizations must also review their certificate management practices and ensure that only trusted certificate authorities are permitted to issue certificates for DirectAccess services.