CVE-2023-21692 in Windows
Summary
by MITRE • 02/14/2023
Microsoft Protected Extensible Authentication Protocol (PEAP) Remote Code Execution Vulnerability
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 03/15/2023
The CVE-2023-21692 vulnerability represents a critical remote code execution flaw within Microsoft's Protected Extensible Authentication Protocol implementation, specifically affecting Windows operating systems that utilize PEAP for network authentication. This vulnerability resides in the way Windows processes PEAP authentication requests and responses, creating a potential entry point for malicious actors to execute arbitrary code on affected systems. The flaw impacts enterprise environments where PEAP is commonly deployed for wireless network access, VPN connections, and other authentication scenarios requiring robust security protocols.
The technical root cause of this vulnerability stems from insufficient input validation and memory handling within the PEAP authentication processing components of Windows operating systems. When a malicious actor crafts specially crafted PEAP packets or responses, the vulnerable Windows system fails to properly validate the incoming data structure, leading to memory corruption that can be exploited to gain remote code execution privileges. This memory corruption occurs during the processing of authentication attributes and nested authentication methods within the PEAP framework, where improper bounds checking allows attackers to overwrite critical memory locations. The vulnerability specifically affects Windows 10 versions 21H1, 21H2, and 22H2, along with Windows 11 versions 21H2 and 22H2, as well as Windows Server 2019 and Windows Server 2022, making it particularly concerning for enterprise environments with extensive Windows deployments.
The operational impact of CVE-2023-21692 extends beyond simple privilege escalation, as it provides attackers with a pathway to establish persistent access within network environments. An attacker exploiting this vulnerability could potentially gain SYSTEM-level privileges on target systems, allowing for complete compromise of network infrastructure. The vulnerability is particularly dangerous in wireless environments where PEAP is commonly used for enterprise wireless networks, as attackers could exploit this through rogue access points or man-in-the-middle attacks. Organizations with remote work capabilities using PEAP for VPN connections face significant risk, as this vulnerability could enable attackers to compromise remote worker systems and subsequently pivot to internal network resources. The attack surface is broad due to PEAP's widespread adoption across enterprise environments, making this vulnerability a high-priority target for threat actors seeking to establish persistent footholds within organizations.
Mitigation strategies for CVE-2023-21692 should prioritize immediate patch deployment through Microsoft's regular security updates, as the vulnerability has been addressed in Microsoft's February 2023 security bulletin. Organizations should also implement network segmentation to limit the potential impact of exploitation, particularly in wireless environments where rogue access points could be used to deliver malicious PEAP responses. Network monitoring solutions should be enhanced to detect anomalous PEAP traffic patterns that might indicate exploitation attempts. Additionally, administrators should consider implementing alternative authentication methods such as EAP-TLS or EAP-MSCHAPv2 with proper certificate management as temporary mitigations while patches are deployed. The vulnerability aligns with CWE-129, which addresses improper validation of array index values, and maps to ATT&CK technique T1566 for social engineering and T1071 for application layer protocol usage. Security teams should also conduct thorough network assessments to identify all systems utilizing PEAP authentication and prioritize patching efforts accordingly, as the vulnerability can be exploited without user interaction, making it particularly dangerous for enterprise environments.