CVE-2023-29062 in FACSChorus
Summary
by MITRE • 11/28/2023
The Operating System hosting the FACSChorus application is configured to allow transmission of hashed user credentials upon user action without adequately validating the identity of the requested resource. This is possible through the use of LLMNR, MBT-NS, or MDNS and will result in NTLMv2 hashes being sent to a malicious entity position on the local network. These hashes can subsequently be attacked through brute force and cracked if a weak password is used. This attack would only apply to domain joined systems.
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Analysis
by VulDB Data Team • 11/29/2023
The vulnerability described in CVE-2023-29062 represents a critical security flaw in network authentication mechanisms that affects systems running the FACSChorus application within domain-joined environments. This weakness stems from improper configuration of the underlying operating system that fails to validate the legitimacy of network resources when credentials are transmitted through specific protocols. The vulnerability specifically targets the authentication process during user interactions with network resources, creating an attack vector that can be exploited by malicious actors positioned within the same local network segment.
The technical implementation of this vulnerability relies on the exploitation of Link-Local Multicast Name Resolution LLMNR, Multicast DNS MBT-NS, and MDNS protocols that are commonly enabled by default on windows operating systems. When users interact with network resources, these protocols attempt to resolve names through broadcast mechanisms that can be intercepted and manipulated by attackers. The operating system configuration allows these protocols to transmit NTLMv2 hash values without proper validation of the intended recipient, effectively creating a man-in-the-middle scenario where authentication credentials are exposed to unauthorized parties. This flaw directly relates to CWE-287 which addresses improper authentication and CWE-312 which covers exposure of sensitive information through cleartext transmission.
The operational impact of this vulnerability extends beyond simple credential theft and represents a significant risk to domain-joined environments where network authentication is critical for maintaining security boundaries. Attackers can leverage this vulnerability to perform offline brute force attacks against captured NTLMv2 hashes, potentially gaining unauthorized access to user accounts with weak passwords. The attack requires minimal privileges and can be executed by any malicious actor within the local network, making it particularly dangerous in shared or untrusted network environments. This vulnerability essentially undermines the security of the entire domain authentication infrastructure by allowing credential exposure at the network layer rather than at the application layer where proper authentication controls should be implemented.
Mitigation strategies for CVE-2023-29062 must focus on disabling or properly configuring the vulnerable protocols while implementing robust network segmentation controls. Organizations should disable LLMNR and NBNS (NetBIOS Name Service) on systems that do not require these services, particularly in domain environments where they pose unnecessary risks. The implementation of proper network access controls through firewalls and network segmentation can prevent unauthorized access to systems within the local network. Additionally, enforcing strong password policies and implementing account lockout mechanisms can significantly reduce the effectiveness of brute force attacks against captured hashes. Security controls should align with the principles outlined in the MITRE ATT&CK framework under the T1566 technique for credential access through network sniffing and credential dumping. Regular network monitoring and anomaly detection systems should be deployed to identify unauthorized use of these protocols and to detect potential exploitation attempts. The vulnerability also highlights the importance of proper system hardening and adherence to security baseline configurations that minimize the attack surface through the elimination of unnecessary network services and protocols.