CVE-2020-0796 Scanner

Microsoft SMBv3 is a protocol used for sharing access to files, printers, and other network resources in Windows environments. It is commonly employed in enterprise and organizational networks where Microsoft Windows is the predominant operating system. SMBv3 helps facilitate network communications, particularly in environments where resources need to be accessed remotely or across connected devices. Primarily maintained by Microsoft, the protocol ensures efficient and secure sharing; however, its vulnerabilities can be critical due to the widespread usage and integral role in network operations. As SMBv3 is deeply embedded in Windows operations, any potential vulnerability can result in high-risk exploits, emphasizing the need for security patching. Users and administrators depend heavily on SMBv3 for daily operations and file sharing in both personal and professional settings.

The vulnerability identified in Microsoft SMBv3 can allow attackers to perform remote code execution, making it a critical risk. Remote Code Execution vulnerabilities occur when an attacker can execute malicious code on a vulnerable system remotely, potentially leading to unauthorized control or data theft. This particular vulnerability can be triggered by sending specially crafted requests to a vulnerable Microsoft Server Message Block 3.1.1 client or server. The vulnerability exploits how certain requests are processed by the protocol, allowing attackers to execute arbitrary code with high privileges. This increases the security risk, as successful exploitation can provide full control over an affected system. Mitigation often requires timely patching and updating of vulnerable systems to prevent exploitation.

The vulnerability in this scenario exists due to improper handling of certain network requests by the Microsoft Server Message Block 3.1.1 protocol. Specifically, a lack of bounds checking or validation in the protocol processing can be leveraged to inject and execute arbitrary code. This can potentially be achieved through carefully crafted packet streams that trigger the exploitable condition. The SMBv3 endpoint affected is the one configured to handle incoming SMB traffic on port 445, commonly used for this protocol. Attackers can leverage compromised code sequences loaded onto the system to escalate privileges or manipulate system operations. The vulnerability is severe, and it requires attackers to have no prior authentication, thereby increasing its exploitability.

Exploiting this vulnerability can have severe impacts on vulnerable systems. Once exploited, an attacker can gain unauthorized access, potentially leading to data exposure, loss of system integrity, and the ability to execute malicious commands or software on the compromised system. The outcome can be full system compromise, where the attacker gains administrative rights over the networked system. Organizations might face data breaches, sensitive information loss, or even disruption of services. This underlines the importance of addressing the vulnerability to maintain operational security and avoid potentially significant damages.

REFERENCES

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-0796
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0796
• https://github.com/tdevworks/CVE-2020-0796-SMBGhost-Exploit-Demo
• http://packetstormsecurity.com/files/156731/CoronaBlue-SMBGhost-Microsoft-Windows-10-SMB-3.1.1-Proof-Of-Concept.html
• http://packetstormsecurity.com/files/156980/Microsoft-Windows-10-SMB-3.1.1-Local-Privilege-Escalation.html