CVE-2023-35366 in Windows
Summary
by MITRE • 07/11/2023
Windows Routing and Remote Access Service (RRAS) Remote Code Execution Vulnerability
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Analysis
by VulDB Data Team • 07/30/2023
The Windows Routing and Remote Access Service (RRAS) represents a critical component within Microsoft's networking infrastructure that provides essential routing capabilities and remote access services for enterprise environments. This service operates as a Windows feature that enables various network functions including routing between different network segments, remote access to corporate networks through dial-up connections, and support for various protocols such as PPP, L2TP, and PPTP. The vulnerability in question stems from improper validation of user-supplied data within the RRAS service implementation, specifically affecting how the service processes certain network requests and authentication parameters. When exploited, this flaw allows an unauthenticated remote attacker to execute arbitrary code on the target system with the highest privileges available to the RRAS service, which typically runs with SYSTEM level permissions.
The technical nature of this vulnerability involves a buffer overflow condition that occurs when the RRAS service processes malformed input data during network protocol handling. This type of flaw falls under the Common Weakness Enumeration category 121 which describes buffer overflows in software implementations where insufficient bounds checking allows attackers to write beyond allocated memory regions. The specific implementation issue manifests when the RRAS service fails to properly validate the length and content of incoming packets or configuration parameters, particularly those related to routing protocols or authentication exchanges. Attackers can craft malicious network packets that trigger this overflow condition, potentially leading to arbitrary code execution within the context of the RRAS service process.
The operational impact of this vulnerability extends beyond simple remote code execution as it fundamentally compromises the security posture of affected systems and networks. Since RRAS typically operates with elevated privileges and may be deployed on critical network infrastructure components, successful exploitation can provide attackers with complete control over routing decisions, access to internal network segments, and potential lateral movement capabilities within the enterprise environment. The vulnerability affects multiple Windows versions including Windows Server 2012, 2012 R2, 2016, 2019, and 2022, making it particularly dangerous for organizations that maintain legacy systems or have not yet fully migrated to newer platforms. Network administrators may find their systems compromised without detection since the attack vectors can be subtle and may not immediately trigger obvious network disruptions.
Mitigation strategies for this vulnerability require immediate action through Microsoft's security patches and updates, which address the underlying buffer overflow conditions in the RRAS service implementation. Organizations should prioritize patching all affected systems as part of their regular security maintenance procedures and consider implementing network segmentation to limit access to RRAS services to trusted networks only. The mitigation approach aligns with the ATT&CK framework's mitigation strategies for remote code execution vulnerabilities where network boundaries and privilege controls play crucial roles in preventing exploitation. Additionally, monitoring network traffic for unusual patterns related to RRAS protocols and implementing intrusion detection systems can help identify potential exploitation attempts. Organizations should also consider disabling unnecessary RRAS functionality or services that are not actively required, reducing the attack surface while maintaining essential networking capabilities. The vulnerability highlights the importance of proper input validation and memory safety practices in critical system components, as outlined in industry security standards that emphasize defending against buffer overflow attacks through code review processes and automated testing procedures.