Vulnerability Scan Result
| Title: | businesopen.nl |
| Description: |
| ip_address | 185.17.187.145 |
| country | NL  |
| network_name | Leaseweb Netherlands B.V. |
| asn | AS60781 |
21/tcp | ftp | Pure-FTPd - |
22/tcp | ssh | OpenSSH 8.9p1 Ubuntu 3ubuntu0.15 |
25/tcp | smtp | Exim smtpd 4.99.2 |
53/tcp | domain | ISC BIND 9.18.39-0ubuntu0.22.04.3 |
80/tcp | http | nginx - |
110/tcp | pop3 | Dovecot DirectAdmin pop3d - |
143/tcp | imap | Dovecot imapd - |
443/tcp | https | nginx - |
465/tcp | smtp | Exim smtpd 4.99.2 |
587/tcp | smtp | Exim smtpd 4.99.2 |
993/tcp | imap | Dovecot imapd - |
995/tcp | pop3 | Dovecot DirectAdmin pop3d - |
2222/tcp | EtherNetIP-1 | - - |
| Software / Version | Category |
|---|---|
| Google Font API | Font scripts |
| Nginx | Web servers, Reverse proxies |
Web Application Vulnerabilities
Evidence
| Software / Version | Category |
|---|---|
| Google Font API | Font scripts |
| Nginx | Web servers, Reverse proxies |
Vulnerability description
We noticed that server software and technology details are exposed, potentially aiding attackers in tailoring specific exploits against identified systems and versions.
Risk description
The risk is that an attacker could use this information to mount specific attacks against the identified software type and version.
Recommendation
We recommend you to eliminate the information which permits the identification of software platform, technology, server and operating system: HTTP server headers, HTML meta information, etc.
Classification
| CWE | CWE-200 |
| OWASP Top 10 - 2017 | |
| OWASP Top 10 - 2021 |
Evidence
| URL | Evidence |
|---|---|
| https://businesopen.nl/ | Response headers do not include the Referrer-Policy HTTP security header as well as the |
Vulnerability description
We noticed that the target application's server responses lack the Referrer-Policy HTTP header, which controls how much referrer information the browser will send with each request originated from the current web application.
Risk description
The risk is that if a user visits a web page (e.g. "http://example.com/pricing/") and clicks on a link from that page going to e.g. "https://www.google.com", the browser will send to Google the full originating URL in the `Referer` header, assuming the Referrer-Policy header is not set. The originating URL could be considered sensitive information and it could be used for user tracking.
Recommendation
The Referrer-Policy header should be configured on the server side to avoid user tracking and inadvertent information leakage. The value `no-referrer` of this header instructs the browser to omit the Referer header entirely.
Classification
| CWE | CWE-693 |
| OWASP Top 10 - 2017 | |
| OWASP Top 10 - 2021 |
Evidence
| URL | Evidence |
|---|---|
| https://businesopen.nl/ | Response headers do not include the HTTP Strict-Transport-Security header |
Vulnerability description
We noticed that the target application lacks the HTTP Strict-Transport-Security header in its responses. This security header is crucial as it instructs browsers to only establish secure (HTTPS) connections with the web server and reject any HTTP connections.
Risk description
The risk is that lack of this header permits an attacker to force a victim user to initiate a clear-text HTTP connection to the server, thus opening the possibility to eavesdrop on the network traffic and extract sensitive information (e.g. session cookies).
Recommendation
The Strict-Transport-Security HTTP header should be sent with each HTTPS response. The syntax is as follows: `Strict-Transport-Security: max-age=<seconds>[; includeSubDomains]` The parameter `max-age` gives the time frame for requirement of HTTPS in seconds and should be chosen quite high, e.g. several months. A value below 7776000 is considered as too low by this scanner check. The flag `includeSubDomains` defines that the policy applies also for sub domains of the sender of the response.
Classification
| CWE | CWE-693 |
| OWASP Top 10 - 2017 | |
| OWASP Top 10 - 2021 |
Evidence
| URL | Evidence |
|---|---|
| https://businesopen.nl/ | Response does not include the HTTP Content-Security-Policy security header or meta tag |
Vulnerability description
We noticed that the target application lacks the Content-Security-Policy (CSP) header in its HTTP responses. The CSP header is a security measure that instructs web browsers to enforce specific security rules, effectively preventing the exploitation of Cross-Site Scripting (XSS) vulnerabilities.
Risk description
The risk is that if the target application is vulnerable to XSS, lack of this header makes it easily exploitable by attackers.
Recommendation
Configure the Content-Security-Header to be sent with each HTTP response in order to apply the specific policies needed by the application.
Classification
| CWE | CWE-1021 |
| OWASP Top 10 - 2017 | |
| OWASP Top 10 - 2021 |
Evidence
| URL | Evidence |
|---|---|
| https://businesopen.nl/ | Response headers do not include the X-Content-Type-Options HTTP security header |
Vulnerability description
We noticed that the target application's server responses lack the X-Content-Type-Options header. This header is particularly important for preventing Internet Explorer from reinterpreting the content of a web page (MIME-sniffing) and thus overriding the value of the Content-Type header.
Risk description
The risk is that lack of this header could make possible attacks such as Cross-Site Scripting or phishing in Internet Explorer browsers.
Recommendation
We recommend setting the X-Content-Type-Options header such as `X-Content-Type-Options: nosniff`.
Classification
| CWE | CWE-693 |
| OWASP Top 10 - 2017 | |
| OWASP Top 10 - 2021 |
Vulnerability description
We have noticed that the server is missing the security.txt file, which is considered a good practice for web security. It provides a standardized way for security researchers and the public to report security vulnerabilities or concerns by outlining the preferred method of contact and reporting procedures.
Risk description
There is no particular risk in not having a security.txt file for your server. However, this file is important because it offers a designated channel for reporting vulnerabilities and security issues.
Recommendation
We recommend you to implement the security.txt file according to the standard, in order to allow researchers or users report any security issues they find, improving the defensive mechanisms of your server.
Classification
| CWE | CWE-1188 |
| OWASP Top 10 - 2017 | |
| OWASP Top 10 - 2021 |
Evidence
| URL | Method | Summary |
|---|---|---|
| https://businesopen.nl/ | OPTIONS | We did a HTTP OPTIONS request. The server responded with a 200 status code and the header: `Allow: HEAD,GET,POST,OPTIONS` Request / Response |
Vulnerability description
We have noticed that the webserver responded with an Allow HTTP header when an OPTIONS HTTP request was sent. This method responds to requests by providing information about the methods available for the target resource.
Risk description
The only risk this might present nowadays is revealing debug HTTP methods that can be used on the server. This can present a danger if any of those methods can lead to sensitive information, like authentication information, secret keys.
Recommendation
We recommend that you check for unused HTTP methods or even better, disable the OPTIONS method. This can be done using your webserver configuration.
Classification
| CWE | CWE-16 |
| OWASP Top 10 - 2017 | |
| OWASP Top 10 - 2021 |
Infrastructure Vulnerabilities
Evidence
We managed to detect a publicly accessible SSH service. Starting Nmap ( https://nmap.org ) at 2026-05-18 23:07 EEST Nmap scan report for businesopen.nl (185.17.187.145) Host is up (0.0079s latency). rDNS record for 185.17.187.145: mail.newdream.nl
PORT STATE SERVICE VERSION 22/tcp open ssh OpenSSH 8.9p1 Ubuntu 3ubuntu0.15 (Ubuntu Linux; protocol 2.0) | ssh-auth-methods: | Supported authentication methods: | publickey |_ password Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ . Nmap done: 1 IP address (1 host up) scanned in 0.98 seconds
Vulnerability description
We found that the SSH service with username/password authentication is publicly accessible. Network administrators often use remote administration protocols to control devices like switches, routers, and other essential systems. However, allowing these services to be accessible via the Internet can increase security risks, creating potential opportunities for attacks on the organization.
Risk description
Exposing this service online with username/password authentication can enable attackers to launch authentication attacks, like guessing login credentials, and potentially gaining unauthorized access. Vulnerabilities, such as unpatched software, protocol flaws, or backdoors could also be exploited. An example is the CVE-2024-3094 (XZ Utils Backdoor) vulnerability.
Recommendation
We recommend turning off SSH with username/password authentication access over the Internet and instead using a Virtual Private Network (VPN) that mandates two-factor authentication (2FA). If the SSH service is essential for business purposes, we recommend limiting access only from designated IP addresses using a firewall. Furthermore, it is advisable to utilize SSH Public Key Authentication since it employs a key pair to verify the identity of a user or process.
Evidence
| Domain Queried | DNS Record Type | Description | Value |
|---|---|---|---|
| businesopen.nl | SPF | Sender Policy Framework | "v=spf1 a mx ip4:185.17.187.145 ~all" |
Vulnerability description
We found that the Sender Policy Framework (SPF) record for the domain is configured with ~all (soft fail), which indicates that emails from unauthorized IP addresses are not explicitly denied. Instead, the recipient mail server is instructed to treat these messages with suspicion but may still accept them. This configuration may not provide enough protection against email spoofing and unauthorized email delivery, leaving the domain more vulnerable to impersonation attempts.
Risk description
The ~all directive in an SPF record allows unauthorized emails to pass through some email servers, even though they fail SPF verification. While such emails may be marked as suspicious or placed into a spam folder, not all mail servers handle soft fail conditions consistently. This creates a risk that malicious actors can spoof the domain to send phishing emails or other fraudulent communications, potentially causing damage to the organization's reputation and leading to successful social engineering attacks.
Recommendation
We recommend changing the SPF record's ~all (soft fail) directive to -all (hard fail). The -all setting tells recipient mail servers to reject emails from any IP addresses not listed in the SPF record, providing stronger protection against email spoofing. Ensure that all legitimate IP addresses and services that send emails on behalf of your domain are properly included in the SPF record before implementing this change.
Evidence
| DKIM selector | Key type | Key size | Value |
|---|---|---|---|
| x | rsa | 786 | "v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAppYZi3Ed/DGpNXad2aMl9PBsPxlBmwEEano04KX3Bz+wdFRg/ZFFWDzLKrqsg607zVk1ggiTH9QLeHSksBsuMAK" "lXng7dr3DqcuxXkUYZjo4zJRabfByp3THLpgSEbBQqsdbtYeHVLjmI6dlC6/qcebNDg84ryhinrnvuQApJIPsKTzYCJ9B40NYqpWKL3uidTcHlAAKjJOqyqwZm/zDttJFspQADdDU88ZQ2pkGuuJLa" "ngc6mTdS6zs8QERQ+EznSa/NsoIzNPaQ6QztbIb/AuneEpG3Btj4yjheJMnpeOJH3if256s1g7LCfYO9OACJSMLzmJVVEK1J0z20thV/wIDAQAB" |
Vulnerability description
We found that the DKIM key length is under 1024-bit. When a DKIM (DomainKeys Identified Mail) key length is under 1024-bit, it is considered weak by modern cryptographic standards. Shorter key lengths, such as 512 or 768 bits, are vulnerable to brute-force attacks, where an attacker could potentially forge a valid DKIM signature for a domain. This undermines the entire purpose of DKIM, which is to authenticate email messages and prevent email spoofing by verifying that the message headers have not been tampered with. A DKIM key under 1024 bits significantly reduces the difficulty for attackers to break the signature.
Risk description
The primary risk of using a DKIM key with fewer than 1024 bits is that it weakens the domain's email authentication security, making it more susceptible to brute-force attacks. If an attacker successfully forges a DKIM signature, they can impersonate legitimate senders and send fraudulent or phishing emails that appear authentic to the recipient. This can lead to financial losses, reputational damage, and an increased risk of targeted attacks, as recipients are more likely to trust emails that pass DKIM verification.
Recommendation
We recommend using a DKIM key with a length of at least 1024 bits. Ideally, 2048-bit keys should be used, as they provide a higher level of security and are more resistant to brute-force attacks. Organizations should regularly audit their DKIM configurations and rotate cryptographic keys periodically to maintain security. In addition, any DKIM keys that are less than 1024 bits should be immediately replaced with stronger keys to prevent exploitation.
Evidence
| Domain Queried | DNS Record Type | Description | Value |
|---|---|---|---|
| _dmarc.businesopen.nl | TXT | Text record | "v=DMARC1;p=reject;rua=mailto:info@businesopen.nl;ruf=mailto:info@businesopen.nl;" |
Vulnerability description
We found that the DMARC record for the domain is not configured with sp policy, meaning that no policy is enforced for subdomains. When a DMARC record does not include a subdomain policy (sp directive), subdomains are not explicitly covered by the main domain's DMARC policy. This means that emails sent from subdomains (e.g., sub.example.com) may not be subject to the same DMARC enforcement as the main domain (example.com). As a result, attackers could potentially spoof emails from subdomains without being blocked or flagged, even if the main domain has a strict DMARC policy.
Risk description
Without a subdomain policy (sp directive) in the DMARC record, subdomains are not protected by the same DMARC enforcement as the main domain, leaving them vulnerable to spoofing attacks. This inconsistency can be exploited by attackers to send phishing emails from subdomains, undermining the organization’s overall email security.
Recommendation
To mitigate the risk, we recommend configuring the DMARC record with a subdomain policy by adding the sp=reject or sp=quarantine directive. This will extend DMARC enforcement to all subdomains, preventing spoofing attempts and maintaining consistent security across both the main domain and its subdomains.
Evidence
We managed to detect a publicly accessible File Transfer Protocol (FTP) service. PORT STATE SERVICE VERSION 21/tcp open ftp Pure-FTPd
Vulnerability description
We found that the File Transfer Protocol (FTP) service is publicly accessible. The FTP enables client systems to connect to upload and download files. Nonetheless, FTP lacks encryption for the data exchanged between the server and the client, leaving all transferred data exposed in plaintext.
Risk description
Exposing this service online can enable attackers to execute man-in-the-middle attacks, capturing sensitive user credentials and the contents of files because FTP operates without encryption. The entirety of the communication between the client and the server remains unsecured in plaintext. This acquired information could further facilitate additional attacks within the network.
Recommendation
We recommend turning off FTP access over the Internet and instead using a Virtual Private Network (VPN) that mandates two-factor authentication (2FA). If the FTP service is essential for business purposes, we recommend limiting access only from designated IP addresses using a firewall. Furthermore, utilizing SFTP (Secure File Transfer Protocol) is recommended as this protocol employs encryption to secure data transfers.
Evidence
We managed to detect a publicly accessible Post Office Protocol (POP3) service. Starting Nmap ( https://nmap.org ) at 2026-05-18 23:07 EEST Nmap scan report for businesopen.nl (185.17.187.145) Host is up (0.0074s latency). rDNS record for 185.17.187.145: mail.newdream.nl
PORT STATE SERVICE VERSION 995/tcp open ssl/pop3 Dovecot DirectAdmin pop3d |_pop3-capabilities: USER SASL(PLAIN) CAPA UIDL PIPELINING AUTH-RESP-CODE TOP RESP-CODES
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ . Nmap done: 1 IP address (1 host up) scanned in 6.83 seconds
Vulnerability description
We found that the Post Office Protocol (POP3) service is publicly accessible and doesn’t include STARTTLS capability. Email clients use the Post Office Protocol (POP) to download emails for user accounts. Some POP servers are initially set up to operate over an unsecured protocol. When email clients download email content through this plaintext protocol, it can pose a substantial risk to the organization's network, especially depending on which user account is set to receive the emails.
Risk description
Exposing this service online can enable attackers to conduct man-in-the-middle attacks, thereby gaining access to sensitive user credentials and the contents of emails. Given that POP3 operates via a plaintext protocol, the entirety of the data exchanged between the client and server is left unencrypted. This critical information could then be leveraged in further attacks on the organization's network.
Recommendation
We recommend turning off POP3 access over the Internet and instead using a Virtual Private Network (VPN) that mandates two-factor authentication (2FA). If the POP3 service is essential for business purposes, we recommend limiting access only from designated IP addresses using a firewall. Furthermore, activating STARTTLS capability (switching the connection to a secure communication) or utilizing Secure POP3 (POP3S) is recommended, as this protocol employs encryption.
Evidence
| Software / Version | Category |
|---|---|
| Nginx | Web servers, Reverse proxies |
Vulnerability description
We noticed that server software and technology details are exposed, potentially aiding attackers in tailoring specific exploits against identified systems and versions.
Risk description
The risk is that an attacker could use this information to mount specific attacks against the identified software type and version.
Recommendation
We recommend you to eliminate the information which permits the identification of software platform, technology, server and operating system: HTTP server headers, HTML meta information, etc.
Evidence
| Software / Version | Category |
|---|---|
| Nginx | Web servers, Reverse proxies |
Vulnerability description
We noticed that server software and technology details are exposed, potentially aiding attackers in tailoring specific exploits against identified systems and versions.
Risk description
The risk is that an attacker could use this information to mount specific attacks against the identified software type and version.
Recommendation
We recommend you to eliminate the information which permits the identification of software platform, technology, server and operating system: HTTP server headers, HTML meta information, etc.
Evidence
| DKIM selector | Key type | Key size | Value |
|---|---|---|---|
| x | rsa | 786 | "v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAppYZi3Ed/DGpNXad2aMl9PBsPxlBmwEEano04KX3Bz+wdFRg/ZFFWDzLKrqsg607zVk1ggiTH9QLeHSksBsuMAK" "lXng7dr3DqcuxXkUYZjo4zJRabfByp3THLpgSEbBQqsdbtYeHVLjmI6dlC6/qcebNDg84ryhinrnvuQApJIPsKTzYCJ9B40NYqpWKL3uidTcHlAAKjJOqyqwZm/zDttJFspQADdDU88ZQ2pkGuuJLa" "ngc6mTdS6zs8QERQ+EznSa/NsoIzNPaQ6QztbIb/AuneEpG3Btj4yjheJMnpeOJH3if256s1g7LCfYO9OACJSMLzmJVVEK1J0z20thV/wIDAQAB" |
Evidence
| Operating System | Accuracy |
|---|---|
| Linux 2.6.32 or 3.10 | 94% |
Vulnerability description
OS Detection
Evidence
| Domain Queried | DNS Record Type | Description | Value |
|---|---|---|---|
| businesopen.nl | A | IPv4 address | 185.17.187.145 |
| businesopen.nl | NS | Name server | ns2.newdream.nl |
| businesopen.nl | NS | Name server | ns1.newdream.nl |
| businesopen.nl | MX | Mail server | 10 mail.businesopen.nl |
| businesopen.nl | SOA | Start of Authority | ns1.newdream.nl. hostmaster.businesopen.nl. 2026051305 3600 3600 1209600 86400 |
| businesopen.nl | SPF | Sender Policy Framework | "v=spf1 a mx ip4:185.17.187.145 ~all" |
| _dmarc.businesopen.nl | TXT | Text record | "v=DMARC1;p=reject;rua=mailto:info@businesopen.nl;ruf=mailto:info@businesopen.nl;" |
Risk description
An initial step for an attacker aiming to learn about an organization involves conducting searches on its domain names to uncover DNS records associated with the organization. This strategy aims to amass comprehensive insights into the target domain, enabling the attacker to outline the organization's external digital landscape. This gathered intelligence may subsequently serve as a foundation for launching attacks, including those based on social engineering techniques. DNS records pointing to services or servers that are no longer in use can provide an attacker with an easy entry point into the network.
Recommendation
We recommend reviewing all DNS records associated with the domain and identifying and removing unused or obsolete records.