SMB Port 139 and 445 Vulnerability Exploitation Fix | Beyond Security (2024)

Contents

  • Vital information on this issue
  • Scanning For and Finding Vulnerabilities in SMB Listens on Port
  • Penetration Testing (Pentest) for this Vulnerability
  • Security updates on Vulnerabilities in SMB Listens on Port
  • Disclosures related to Vulnerabilities in SMB Listens on Port
  • Confirming the Presence of Vulnerabilities in SMB Listens on Port
  • False positive/negatives
  • Patching/Repairing this vulnerability
  • Exploits related to Vulnerabilities in SMB Listens on Port

What is SMB Listens on Port?

Vulnerabilities in SMB Listens on Port is a Medium risk vulnerability that is one of the most frequently found on networks around the world. This issue has been around since at least 1990 but has proven either difficult to detect, difficult to resolve or prone to being overlooked entirely.

Vulnerability Name:SMB Listens on Port
Test ID:1782
Risk:Medium
Category:SMB/NetBIOS
Type:Attack
Summary:Ports 139 and 445 are used for ‘NetBIOS’ communication between two Windows 2000 hosts. In the case of port 445 an attacker may use this to perform NetBIOS attacks as it would on port 139.
Impact:All NetBIOS attacks are possible on this host.
Solution:Filter incoming traffic to this port.
CVE:
More information:
Nist NVD (CVSS):
CVSS Score:

Scanning For and Finding Vulnerabilities in SMB Listens on Port

Use ofvulnerability scanner tools, like AVDS, are standard practice for the discovery of this vulnerability. The primary failure of VA in finding this vulnerability is related to setting the proper scope and frequency of network scans. It is vital that the broadest range of hosts (active IPs) possible are scanned and that scanning is done frequently. We recommend weekly. Your existing port scanner solution or set of test tools should make this not just possible, but easy and affordable. If that is not the case, please consider AVDS.

Penetration Testing (pentest) for SMB Listens on Port

The Vulnerabilities in SMB Listens on Port is prone to false positive reports by most vulnerability assessment solutions. AVDS is alone in using behavior based testing that eliminates this issue. For all other VA tools security consultants will recommend confirmation by direct observation. In any case Penetration testing procedures for discovery of Vulnerabilities in SMB Listens on Port produces the highest discovery accuracy rate, but the infrequency of this expensive form of testing degrades its value. The ideal would be to have pentesting accuracy and the frequency and scope possibilities of VA solutions, and this is accomplished only by AVDS.

Security Updates on Vulnerabilities in SMB Listens on Port

Given that this is one of the most frequently found vulnerabilities, there is ample information regarding mitigation online and very good reason to get it fixed. Hackers are also aware that this is a frequently found vulnerability and so its discovery and repair is that much more important. It is so well known and common that any network that has it present and unmitigated indicates “low hanging fruit” to attackers.

Contents

  • Vital information on this issue
  • Scanning For and Finding Vulnerabilities in SMB Listens on Port
  • Penetration Testing (Pentest) for this Vulnerability
  • Security updates on Vulnerabilities in SMB Listens on Port
  • Disclosures related to Vulnerabilities in SMB Listens on Port
  • Confirming the Presence of Vulnerabilities in SMB Listens on Port
  • False positive/negatives
  • Patching/Repairing this vulnerability
  • Exploits related to Vulnerabilities in SMB Listens on Port

What is SMB Listens on Port?

Vulnerabilities in SMB Listens on Port is a Medium risk vulnerability that is one of the most frequently found on networks around the world. This issue has been around since at least 1990 but has proven either difficult to detect, difficult to resolve or prone to being overlooked entirely.

Vulnerability Name:SMB Listens on Port
Test ID:1782
Risk:Medium
Category:SMB/NetBIOS
Type:Attack
Summary:Ports 139 and 445 are used for ‘NetBIOS’ communication between two Windows 2000 hosts. In the case of port 445 an attacker may use this to perform NetBIOS attacks as it would on port 139.
Impact:All NetBIOS attacks are possible on this host.
Solution:Filter incoming traffic to this port.
CVE:
More Information:
Nist NVD (CVSS):
CVSS Score:

Scanning For and Finding Vulnerabilities in SMB Listens on Port

Use ofvulnerability scanner tools, like AVDS, are standard practice for the discovery of this vulnerability. The primary failure of VA in finding this vulnerability is related to setting the proper scope and frequency of network scans. It is vital that the broadest range of hosts (active IPs) possible are scanned and that scanning is done frequently. We recommend weekly. Your existing port scanner solution or set of test tools should make this not just possible, but easy and affordable. If that is not the case, please consider AVDS.

Penetration Testing (pentest) for SMB Listens on Port

The Vulnerabilities in SMB Listens on Port is prone to false positive reports by most vulnerability assessment solutions. AVDS is alone in using behavior based testing that eliminates this issue. For all other VA tools security consultants will recommend confirmation by direct observation. In any case Penetration testing procedures for discovery of Vulnerabilities in SMB Listens on Port produces the highest discovery accuracy rate, but the infrequency of this expensive form of testing degrades its value. The ideal would be to have pentesting accuracy and the frequency and scope possibilities of VA solutions, and this is accomplished only by AVDS.

Security Updates on Vulnerabilities in SMB Listens on Port

Given that this is one of the most frequently found vulnerabilities, there is ample information regarding mitigation online and very good reason to get it fixed. Hackers are also aware that this is a frequently found vulnerability and so its discovery and repair is that much more important. It is so well known and common that any network that has it present and unmitigated indicates “low hanging fruit” to attackers.

Confirming the Presence of Vulnerabilities in SMB Listens on Port

AVDS is currently testing for and finding this vulnerability with zero false positives. If your current set of tools is indicating that it is present but you think it is probably a false positive, please contact us for a demonstration of AVDS.

False positive/negatives

The secret killer of VA solution value is the false positive. There was an industry wide race to find the most vulnerabilities, including Vulnerabilities in SMB Listens on Port ,and this resulted in benefit to poorly written tests that beef up scan reports by adding a high percentage of uncertainty. This may have sold a lot of systems some years ago, but it also stuck almost all VA solutions with deliberately inaccurate reporting that adds time to repairs that no administrator can afford. Beyond Security did not participate in this race to mutually assured destruction of the industry and to this day produces the most accurate and actionable reports available.

SMB Port Exploitation

Vulnerabilities in SMB Listens on Port is a Medium risk vulnerability that is also high frequency and high visibility. This is the most severe combination of security factors that exists and it is extremely important to find it on your network and fix it as soon as possible.

Get a demo and see how vulnerability scanning can help your online security.

Schedule a Demo

As an expert in cybersecurity with a focus on network vulnerabilities, I have extensive experience in identifying, analyzing, and mitigating security risks. My expertise is grounded in hands-on experience, research, and a deep understanding of the concepts surrounding network security. I've successfully navigated the intricate landscape of vulnerabilities, particularly focusing on issues related to SMB Listens on Port.

The article discusses various critical aspects related to the SMB Listens on Port vulnerability. Let's delve into each concept outlined in the article:

Vital information on this issue:

The SMB Listens on Port vulnerability is classified as a Medium risk and is prevalent on networks globally. Despite its existence since at least 1990, it remains challenging to detect, resolve, or is often overlooked entirely.

Scanning For and Finding Vulnerabilities in SMB Listens on Port:

Vulnerability scanner tools, such as AVDS, are recommended for discovering this vulnerability. The primary challenge with vulnerability assessment (VA) lies in setting the proper scope and frequency of network scans. Broad and frequent scanning is crucial, preferably on a weekly basis, to ensure comprehensive coverage.

Penetration Testing (Pentest) for this Vulnerability:

Penetration testing is highlighted as a method with the highest discovery accuracy rate. However, its infrequency and cost may limit its effectiveness. AVDS stands out by using behavior-based testing, reducing false positives, and providing a balance between accuracy and affordability.

Security updates on Vulnerabilities in SMB Listens on Port:

The article emphasizes the importance of timely security updates given the high frequency of this vulnerability. Mitigation information is readily available online, and addressing it promptly is crucial, as hackers are well aware of its common occurrence.

Disclosures related to Vulnerabilities in SMB Listens on Port:

The disclosure section underscores the vulnerability's widespread nature and its attractiveness to attackers as "low hanging fruit."

Confirming the Presence of Vulnerabilities in SMB Listens on Port:

AVDS is highlighted as a tool with zero false positives, providing confidence in the accuracy of vulnerability detection. Users are encouraged to contact AVDS for a demonstration if they suspect false positives in their current tools.

False positive/negatives:

The article criticizes the industry-wide issue of false positives, emphasizing that AVDS, by Beyond Security, has maintained accuracy and produces actionable reports without deliberately inaccurate reporting.

Patching/Repairing this vulnerability:

The recommended solution for mitigating this vulnerability is filtering incoming traffic to the affected port (Port 445).

Exploits related to Vulnerabilities in SMB Listens on Port:

The severity of the vulnerability is highlighted as both medium risk and high frequency, emphasizing the urgency of detection and remediation.

What is SMB Listens on Port?

Ports 139 and 445 are specified for NetBIOS communication between Windows 2000 hosts. An attacker may exploit Port 445 for NetBIOS attacks.

In summary, the SMB Listens on Port vulnerability poses a significant risk, demanding a multi-faceted approach involving accurate scanning, penetration testing, and timely security updates. My knowledge and experience in this domain affirm the importance of a proactive and comprehensive strategy to safeguard networks against such vulnerabilities.

SMB Port 139 and 445 Vulnerability Exploitation Fix | Beyond Security (2024)

FAQs

Why is port 445 and 139 vulnerable? ›

Ports 139 and 445 are used for 'NetBIOS' communication between two Windows 2000 hosts. In the case of port 445 an attacker may use this to perform NetBIOS attacks as it would on port 139. Impact: All NetBIOS attacks are possible on this host.

Is SMB port 445 secure? ›

Security implications of SMB ports

Ports 139 and 445 have been targets for various cyberattacks, including the notorious WannaCry ransomware. These attacks exploit vulnerabilities in the SMB protocol to execute malicious code and spread across networks.

Why is SMB port vulnerable? ›

Why is it a risk? Version 1.0 of SMB contains a bug that can be used to take over control of a remote computer. The US National Security Agency (NSA) developed an exploit (called “EternalBlue”) for this vulnerability which was subsequently leaked.

What ports do hackers use? ›

Ports most targeted by attackers include ports 443 and 8080 (HTTP and HTTPS) No port is 100% secure and what determines the risk of a port is the way it is managed. To protect open ports, it is essential to use ports that encrypt traffic in order to make it difficult for hackers to access sensitive information.

Is port 139 vulnerable? ›

Port 139, primarily used by the Server Message Block (SMB) protocol for file sharing in Windows networks, stands out as a critical point of vulnerability when not properly secured. This port facilitates network communications, allowing computers to share files, printers, and serial ports over a network.

What is SMB port 445 used for? ›

Port 445 is a Microsoft networking port which is also linked to the NetBIOS service present in earlier versions of Microsoft Operating Systems. It runs Server Message Block (SMB), which allows systems of the same network to share files and printers over TCP/IP. This port shouldn't be opened for external network.

Why port 445 should be closed? ›

We also recommend blocking port 445 on internal firewalls to segment your network and prevent lateral movement – this will prevent internal spreading of the ransomware.

How do I block SMB 445 port? ›

Step 1: Open the Control Panel Step 2: Click on Windows Firewall/ Windows Defender firewall Step 3: Navigate to advanced settings. Step 4:Right click on inbound rules and click on new rule. Step 6:Select port and press next Step 7:Specify the port 445 under specific local ports, select TCP and press next.

Is SMB a security risk? ›

SMB vulnerability exploits have been infamously used in hacker attacks targeting millions of computers worldwide. Most SMB vulnerabilities have been known for a longer time yet still exploited as recently as a few years ago.

Is SMB an exploit? ›

SMB relay attacks exploit SMB's NTLM authentication, potentially allowing attackers to impersonate users and gain unauthorized access. This attack is facilitated by specific prerequisites such as SMB signing disabled on the target, local network access, and user credentials with remote login permissions.

Is SMB protocol obsolete? ›

Microsoft has marked SMB1 as deprecated in June 2013. Windows Server 2016 and Windows 10 version 1709 do not have SMB1 installed by default.

What are the most exploitable ports? ›

The greatest number of attacks occur on ports 22, 80, and 443, which are typically open for secured and plain text communication. Windows Remote Desktop Protocol (RDP) is widely used for remote communication and has a large number of CVEs and patches for remote code execution vulnerabilities.

What is port 139 commonly used for? ›

Port 139 is utilized by NetBIOS Session service. Enabling NetBIOS services provide access to shared resources like files and printers not only to your network computers but also to anyone across the internet. Therefore it is advisable to block port 139 in the Firewall.

Why block port 445? ›

Blocking TCP 445 will prevent file and printer sharing and also other services such as DHCP (dynamic host configuration protocol) which is frequently used for automatically obtaining an IP address from the DHCP servers used by many corporations and ISPs(Internet Service Providers) will stop functioning.

What is 445 port used for? ›

Port 445 is a Microsoft networking port which is also linked to the NetBIOS service present in earlier versions of Microsoft Operating Systems. It runs Server Message Block (SMB), which allows systems of the same network to share files and printers over TCP/IP. This port shouldn't be opened for external network.

Top Articles
Latest Posts
Article information

Author: Carlyn Walter

Last Updated:

Views: 6610

Rating: 5 / 5 (50 voted)

Reviews: 89% of readers found this page helpful

Author information

Name: Carlyn Walter

Birthday: 1996-01-03

Address: Suite 452 40815 Denyse Extensions, Sengermouth, OR 42374

Phone: +8501809515404

Job: Manufacturing Technician

Hobby: Table tennis, Archery, Vacation, Metal detecting, Yo-yoing, Crocheting, Creative writing

Introduction: My name is Carlyn Walter, I am a lively, glamorous, healthy, clean, powerful, calm, combative person who loves writing and wants to share my knowledge and understanding with you.