Top 10 Critical Network Pentest Findings IT Teams Overlook

After conducting over 10,000 automated internal network penetration tests last year, a security tool has already found the concerning reality that many businesses still have significant security vulnerabilities that hackers might easily exploit.

Companies often think that endpoint security, firewalls, and SIEMs are enough to keep them safe. But how effective are these protections when put to the test? That can be aided by Craw Security's automated network pentesting solutions, which are provided by a highly skilled group of top-notch penetration testers with years of excellent job experience. Our Red Team of Penetration Testers helps businesses find exploitable vulnerabilities before cybercriminals do by simulating real-world attack scenarios.

These are not complex zero-day exploits. These configuration mistakes, weak passwords, and unpatched vulnerabilities are often used by attackers to gain access to networks, move laterally, and increase privileges. These risks are broken down as follows:

50% stem from misconfigurations	Default settings, loose access controls, and disregarded security protocols.
30% are due to missing patches	Unpatched systems are vulnerable to known flaws.
20% involve weak passwords	Hackers can easily access services that don't use sufficient authentication.

This post will cover the 10 Most Critical Network Pentest Findings or Security Threats, their definitions, the causes of their danger, and ways to stop future problems. We'll start with the least common issue and work our way up to the most common one we've seen in hundreds of penetration test investigations across several IT infrastructures across numerous enterprises. Attackers will eventually find these weaknesses in your system.

1. Multicast DNS (mDNS) Spoofing

CVSS3: 9.8

% of occurrence: 78.2%

What it is:

Multicast DNS (mDNS), a name resolution method for local networks, assists in resolving domain names when a dedicated DNS server is unavailable. The resolution process is divided into phases:

The system first searches its local host file for any pertinent DNS name/IP address mappings.
When a DNS server is not set up, the system uses mDNS. It sends out an IP multicast query requesting self-identification from the host linked to the DNS name. This protocol behavior highlights a potential vulnerability that malicious actors could exploit, enabling them to reply to these questions and seem like reliable services.

Security Impact:

mDNS queries are sent over the local subnet and can be answered by any device that can receive them. This vulnerability allows an attacker to respond with their system's IP address, potentially tricking the machine executing the query. Such exploitation may lead to the capture of sensitive data, including unencrypted and hashed credentials, depending on the specific service the victim is trying to access (e.g., SMB, MSSQL, HTTP). It should be noted that using brute-force attack methods and contemporary computing power, hashed credentials can often be compromised quickly.

Recommendation:

Turning off mDNS completely when not in use is the primary recommendation for lowering the danger of mDNS spoofing. On Windows computers, this is often achieved by activating the 'Disable Multicast Name Resolution' group policy. Since many apps can regain mDNS capabilities, blocking UDP port 5353 with the Windows firewall is an alternative strategy. For non-Windows PCs, disabling apps like Apple Bonjour or Avahi-daemon can provide similar security.

It is important to keep in mind that some conference room technology and features, like screen casting, may be affected if mDNS is turned off. If complete disabling is not feasible, think about isolating affected systems within a restricted network section and mandating the use of strong, complex passwords for any accounts that access these systems.

2. NetBIOS Name Service (NBNS) Spoofing

CVSS3: 9.8

% of occurrence: 73.3%

What is it:

Workstations connected to an internal network employ the NetBIOS Name Service (NBNS) protocol to resolve domain names in the event that a DNS server is inaccessible or unresponsive. When a system tries to resolve a DNS name, it does the following:

The system first searches its local host file for an item that matches the DNS name to an IP address.
If there isn't a local mapping, the system sends a DNS query to the DNS server or servers it has selected in an attempt to find the corresponding IP address.
If the DNS server or servers are unable to resolve the name, the system sends an NBNS query over the local network, requesting responses from other computers.

The NBNS is vulnerable to spoofing attacks because of its dependency on broadcasts, where a hacker may respond with a fake IP address.

Security Impact:

Any system on the local network can respond to NBNS requests since they are broadcast. By answering these queries with the IP address of the attacker's system, malicious actors may exploit this vulnerability to reroute traffic intended for legitimate services. For instance, services like SMB, MSSQL, or HTTP may inadvertently send private data, including hashed account passwords or cleartext, to the attacker's computer. Furthermore, modern computational power makes it easier to crack hashed credentials, which could give unauthorized individuals access to their accounts.

Recommendation:

To lessen the risk of NBNS spoofing, it is recommended to disable the NetBIOS service on every host in the internal network. This can be accomplished through a variety of methods, including system registry updates, network adapter settings adjustments, and DHCP option configuration. The potential attack surface associated with NBNS will be significantly reduced by implementing these changes.

3. Link-Local Multicast Name Resolution (LLMNR) Spoofing

CVSS3: 9.8

% of occurrence: 65.5%

What is it:

When traditional Domain Name System (DNS) services are ineffective or unavailable, a protocol known as Link-Local Multicast Name Resolution (LLMNR) was developed to resolve names in internal network settings. LLMNR facilitates DNS name resolution with multicast queries as a backup technique. The resolution process proceeds as follows:

The system first looks through its local host file for an IP address that matches the supplied DNS name.
If there isn't a local record, the system resolves the name by sending a DNS query to its specified DNS server or servers.
If the DNS server or servers are unable to provide a resolution, the system sends an LLMNR query throughout the local network to see if other hosts can reply.

This reliance on multicast broadcasts poses dangers because any active system can respond to the queries and perhaps trick the asking system.

Security Impact:

LLMNR questions are broadcast; thus, any system on the local network can respond to a resolution request using its own IP address. Malicious actors can exploit this by delivering well-crafted responses that contain the address of the attacker's system. This feature makes it possible for significant security flaws, particularly if the query is linked to vital services like SMB, MSSQL, or HTTP. A successful redirection may facilitate the acquisition of private information, including plaintext and hashed account passwords. It is crucial to keep in mind that hashed credentials are susceptible to modern brute-force attacks, endangering account security.

Recommendation:

To lessen the risks associated with LLMNR spoofing, all affected systems must have their LLMNR capabilities disabled. This can be accomplished using the following methods:

Group Policy Configuration	Set ‘Turn off Multicast Name Resolution’ to Enabled under Computer Configuration\Administrative Templates\Network\DNS Client. Use the Remote Server Administration Tools for Windows 7 found at this URL to manage settings on a Windows Server 2003 domain controller.
Registry Modification for Windows Vista/7/10 Home Edition	For the purpose of disabling the capability, go to HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient and change the 'EnableMulticast' key to 0 or remove it.

4. IPv6 DNS Spoofing

CVSS3: 10.0

% of occurrence: 49.9%

What is it:

IPv6 DNS spoofing would become more dangerous if a rogue DHCPv6 server were to enter the internal network architecture. Since Microsoft Windows systems prefer IPv6 over IPv4, IPv6-capable clients are likely to obtain their IP address configurations from any accessible DHCPv6 server.

Security Impact:

A rogue DHCPv6 server can manipulate DNS requests by rerouting IPv6-enabled clients to use the attacker's system as their DNS server. This ability could have serious consequences, such as the unlawful acquisition of personal data, such as user credentials. If all DNS requests resolve to the attacker's server, the victim's system may inadvertently communicate with malicious services operating on the attacker's infrastructure, such as platforms like SMB, HTTP, RDP, and MSSQL.

Recommendation:

The following strategies are recommended to lessen the risks associated with IPv6 DNS spoofing, with an emphasis on synchronizing each method with organizational operations and doing thorough testing prior to implementation:

Manage Rogue DHCP at the Network Layer	Incorporate features like DHCP authentication, DHCP snooping, and Rogue DHCP detection on network switches and firewalls to control unauthorized DHCP servers and lessen the likelihood of DNS spoofing attacks.
Prefer IPv4 over IPv6	To configure Windows machines to prefer IPv4 over IPv6, use Group Policy Preferences (GPPs) or Group Policy Objects (GPOs). It is important to keep in mind that attacks on non-Windows devices won't be prevented by this tactic.
Disable IPv6	For Microsoft Windows systems, disabling IPv6 is typically not recommended, while it may be a last resort if thorough testing ensures that there won't be any significant delays to business operations.

5. Outdated Microsoft Windows Systems

CVSS3: 9.8

% of occurrence: 24.9%

What is it:

Outdated Windows computers provide significant security risks since Microsoft no longer offers necessary upgrades. These systems are more susceptible to attack because they may not have the security fixes deployed to address known vulnerabilities. Additionally, a lack of updates could lead to issues with modern security software and technologies, further undermining the system's defenses. Attacks such as data exfiltration, virus distribution, and unauthorized access can often exploit vulnerabilities in antiquated systems.

Security Impact:

If an outdated Microsoft Windows system is exploited, an attacker may get unauthorized access to the compromised system or systems and reveal personal data and resources. Furthermore, an attacker might exploit a compromised system or systems as an entry point to migrate laterally, compromising further systems and extending the breach's whole footprint because systems inside the same network may have identical settings.

Recommendation:

Replacing outdated Microsoft Windows versions with the most recent operating system or systems that the manufacturer still supports is strongly recommended. After doing a thorough inventory of all systems to identify and prioritize outdated versions, this should entail implementing a phased upgrading strategy. Make sure all systems are regularly receiving the most recent patches and updates in order to maintain security integrity.

6. IPMI Authentication Bypass

CVSS3: 10.0

% of occurrence: 15.7%

What is it:

The Intelligent Platform Management Interface (IPMI) is a crucial piece of hardware used by network managers for centralized server control. Hackers may be able to remotely circumvent the authentication method due to weaknesses in the configuration of the server or servers with IPMI installed. Password hashes are thus recovered, and attackers may be able to obtain the cleartext passwords in cases where weak or default hashing algorithms are employed.

Security Impact:

The ability to extract cleartext passwords is a significant security risk since an attacker might use this knowledge to gain unauthorized remote access to sensitive services like Secure Shell (SSH), Telnet, or web-based interfaces. The availability and consistency of services provided by the compromised server or servers could be negatively impacted by such unauthorized access, which could allow configurations to be changed.

Recommendation:

This vulnerability cannot be fixed; hence, one or more of the following mitigation strategies must be applied:

Permit IPMI access only to authorized systems that require administrative functionality.

● Turn down IPMI service on the server or servers that are not needed for business operations.

● Replace the default administrator password or passwords with complex, secure ones to increase security.

● To lessen the chance of man-in-the-middle attacks that could expose sensitive information, use secure connection techniques like SSH and HTTPS.

7. Microsoft Windows RCE (EternalBlue)

CVSS3: 9.8

% of occurrence: 4.5%

What is it:

EternalBlue is a remote code execution vulnerability in the Microsoft Server Message Block (SMBv1) protocol. Enabling an attacker to send specially generated packets to a vulnerable system, it permits illicit entry and the execution of arbitrary code with system-level privileges.

Security Impact:

By exploiting the EternalBlue vulnerability, an attacker can gain full administrative access to the compromised machine or systems. This access may facilitate additional hostile operations within the company's network, including lateral migration to other systems and the extraction of password hashes and cleartext passwords. Importantly, because this vulnerability does not need the attacker to elevate privileges on the compromised machine, they can launch reconnaissance and other attacks with minimal extra effort.

Recommendation:

Reducing the risk associated with the EternalBlue vulnerability requires applying the required security updates to all affected computers as soon as possible. A thorough assessment of the company's patch management practices should also be conducted in order to identify any vulnerabilities that led to these systems remaining unpatched. The significant danger and frequent exploitation of this vulnerability necessitate immediate corrective action.

8. Microsoft Windows RCE (BlueKeep)

CVSS3: 9.8

% of occurrence: 4.4%

What is it:

BlueKeep is a remote code execution vulnerability in Microsoft's Remote Desktop Protocol (RDP) that is categorized as CVE-2019-0708.

Security Impact:

By exploiting the BlueKeep vulnerability, an attacker can get complete control over the compromised machine or systems. This level of access may facilitate further attacks on the company's infrastructure, including the potential extraction of sensitive data such as hashes and passwords. Additionally, the attacker may be able to compromise additional systems and services by moving laterally across the network. Because no particular privileges or authenticated access are required to execute the attack, the vulnerability's nature makes the attacker's job easier and increases the potential harm to the company.

Recommendation:

Any relevant security updates must be implemented to the affected system or systems as soon as feasible in order to reduce the BlueKeep vulnerability. Organizations should carefully review their patch management practices to identify the causes of the delayed updates. Because of the vulnerability's exploitability and potential to seriously harm systems, the organization's digital environment needs to be safeguarded right now.

9. Firebird Servers Accept Default Credentials

CVSS3: 9.0

% of occurrence: 1.4%

What is it:

Default credentials, which are occasionally hard-coded usernames and passwords intended for initial setup, should be changed as soon as feasible to maintain security. This issue arises when systems are deployed without reconfiguration or when default settings are overlooked during setup.

Security Impact:

Using the default credentials for Firebird servers could lead to unauthorized access, allowing hackers to gain access and investigate the affected networks. They might alter system settings or list files, opening the door for further misuse. If an attacker discovers the location of Firebird database files, they might be able to view or change private database data. By using particular Firebird versions to execute system commands, an attacker can also get further control over the remote computer.

Recommendation:

Reducing this problem requires using the GSEC tool to change the default credentials of the Firebird servers. Establishing a procedure for regular credential checks and ensuring that all default settings are modified before deployment will further enhance security. Turning on alerts for suspicious behavior and routinely reviewing server access logs for unauthorized attempts might help identify potential exploits early.

10. Password Deficiencies - Redis Service

CVSS3: 9.9

% of occurrence: 1.3%

What is it:

Redis is a popular in-memory key-value data store for caching, message brokering, and real-time analytics. Because Redis does not by default need authentication, clients can connect without providing login credentials.

Security Impact:

An intruder may be able to access sensitive data stored in the server's databases and possibly escalate privileges to get system-level access, depending on the capabilities of the Redis service and the authorizations associated with the compromised user account. This could lead to unauthorized data modification, data exfiltration, or other system exploitation.

Recommendation:

Strong passwords that adhere to the organization's password policy are crucial for configuring the Redis service. The following criteria should be met by a strong password:

● A minimum of twelve characters.

● Not readily guessed, for example, not in a dictionary.

● Combination of special characters, numbers, capital and lowercase letters, and/or

● Checkable against databases of known compromised passwords (such as www.haveibeenpwned.com)

Using a password manager can further increase security by generating complex passwords that are difficult to retrieve, even if the password hash is found through a hack.

What Pentesting Reveals About Security Gaps?

Tens of thousands of network evaluations have been analyzed, and one thing is clear: rather than complex hacking methods, many security problems are the result of simple, avoidable mistakes. Weak passwords, forgotten configurations, and unpatched systems are all easily exploited by attackers. These weaknesses don't happen once in a lifetime. These are recurring problems that occur in networks of all sizes every year.

Pentesting is akin to testing your security before a real attacker does. It demonstrates how someone may use the same tactics used by real attackers to get in, move around, and gain more privileges. Evaluations have consistently demonstrated that even companies with strong security often contain unidentified weaknesses that are simply waiting to be exploited.

The problem? There are months of blind spots in between because most companies still rely on annual pentests to verify compliance. Craw Security is actually able to assist with that. Instead of waiting for an audit to show what went wrong, you can find and fix exploitable vulnerabilities all year long with its automatic, on-demand network pentesting.

Cyber threats shouldn't force security testing to slow down. To stay ahead of attackers and not just check a compliance box, regular network pentesting—whether automated or human—is crucial. Would you like to learn more about our penetration testing methodologies, duly customized for your IT Security enhancement, and experience the effectiveness of our world-class network pentesting?

Make an appointment for a free security check demo just by calling our 24X7 hotline mobile number, +91-9513805401! You may also make the call or text over WhatsApp on the same number if you are an international caller. The highly talented and experienced penetration testers at Craw Security, the Best VAPT Solutions Provider in India and other prominent nations worldwide, will work on the varied IoT gadgets over your IT infrastructure to hone the security algorithms for a better security posture.

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