What is an SMB Protocol Vulnerability, what is the risk and how can you mitigate that risk? - Skyway West (2024)

FAQs

What is SMB protocol vulnerability? ›

It resides within the SMBv3 protocol and can affect newer systems, such as Windows 10 and Windows Server 1903 and 1909. An attacker exploiting this vulnerability can send a specially designed SMBv3 packet to a vulnerable server. Victims who connect to the server are then exposed to remote code execution.

How can you mitigate the risk? The best approach is to not allow SMB across the Internet using firewall rules; either disallow all traffic on ports 135-139 & 445 or limit access to specific IP addresses or Mac Addresses.

The Server Message Block (SMB) protocol is a client-server communication protocol that is used for shared access to files, directories, printers, serial ports, and other resources on a network. It also provides an authenticated inter-process communication (IPC) mechanism.

Leaving an SMB service open to the public can give attackers the ability to access data on your clients' internal network, and increases their risk of a ransomware attack or other exploit.

SMB signing disabled vulnerability is a security vulnerability that allows an attacker to bypass SMB signing and modify the data in transit. This vulnerability can be exploited by attackers to gain unauthorized access to sensitive information or to carry out other malicious activities.

SMB is used for sharing resources within a local network, such as files, printers, and serial ports. SMB offers additional features such as file locking, making it better suited for collaboration. FTP is simply a means of transferring files from one location to another, while SMB is more robust and feature-rich.

Step 1: Open control panel Step 2: Navigate to programs and features. Step 3: Click on "Turn Windows features on or off. Step 4: Disable "(Server Message Block) SMB v1"Step 5 : Click ok.

Small And Midsize Business (SMB)

The attribute used most often is number of employees; small businesses are usually defined as organizations with fewer than 100 employees; midsize enterprises are those organizations with 100 to 999 employees.

The cybersecurity implications of Samba ports

From a cybersecurity perspective, open or poorly secured Samba ports can pose significant risks to organizational networks. They can be exploited by cybercriminals to gain unauthorized access, conduct reconnaissance activities, spread malware, or launch ransomware attacks.

SMB works at Layer 7, the application layer, and uses TCP/IP on port 445 (note: prior to Windows 2000 the SMB port number was 139).

What is the disadvantage of SMB? ›

There are some drawbacks to SMB. For example, it should not be used across the internet, but only on hosts connected to the LAN. This is due to the inherent insecurity of the way SMB authenticates. Although it is still apparent on a LAN, the attack surface is greatly reduced.

So SFTP is far more secure overall thanks to its use of SSH encryption. SMB versions earlier than 3.0 lack encryption by design but can be secured by layering the proper tools.

To remotely access data on your Synology NAS via SMB, we recommend using a virtual private network (VPN) for secure connection. This article guides you through setting up a VPN. Notes: Avoid exposing the CIFS/SMB ports of your Synology NAS to the Internet to prevent ransomware attacks.

SMB serves as a legitimate means for file sharing and communication between devices in networks. Malware's spread isn't a flaw in the SMB protocol itself; rather, it seizes upon vulnerabilities or credential misuse. The SMB protocol, fundamentally, is secure.

SMB is a main feature of the Microsoft Windows network services and is therefore particularly suited for communication between Windows computers. DSM uses the SMB protocol as a standard network communication. The Hypertext Transfer Protocol (HTTP,) is a protocol used to transfer data across a network.

Before Christmas 2022, there was a truly nasty security hole in the Linux 5.15 in-kernel Server Message Block (SMB) server, ksmbd. It could be used to execute code in the kernel context. In short: Bad. But, the newest ksmbd security problem, discovered by the Sysdig Threat Team, is relatively minor.

Specifically, the issue arises when the software handles a specially crafted 'pathname' in an SMB request. An authenticated attacker can exploit this issue to trigger a buffer-overflow condition and execute arbitrary code. Successful exploits will allow the attacker to execute code with SYSTEM-level privileges.