Fix: ERR_UNSAFE_PORT

There have been some reports about, users who are trying to connect to a web server with different ports but getting an error “ERR_UNSAFE_PORT”. This is because of using the unsafe port on your browser, which is not letting you through for security purpose.

What causes the ERR_UNSAFE_PORT error?

This error is caused because your browser is stopping you to access the unsafe ports. Web developers are aware of the security and that browser is incredibly obliging to attackers when it comes to making a request on servers on your behalf. Through the unsafe ports, attackers can trick the web browser into something that can be harmful for the user.

Allowing Unsafe/Restricted ports on your Browser

To fix this error, you need to explicitly allow the unsafe ports that you are trying to access on your browser. Different browsers will have different methods of allowing restricted ports access. Below we will guide you about Chrome and Firefox methods:

For Chrome:

To allow ports in chrome, you just need to go in the properties of Chrome shortcut and add the following line in the shortcut target with the port you want to access.

1. Right click on Chrome Shortcut
2. Select Properties
3. Now Append —explicitly-allowed-ports=xxx to shortcut target
   Example:

   C:\Program Files (x86)\Google\Chrome\Application\chrome.exe --explicitly-allowed-ports=6666 

   

   Note: there are two ” – – ” dash without spaces before the word explicitly.
   You can also add multiple ports by using the comma between them.

For Firefox:

For Firefox, you can allow the ports by using the network.security.ports.banned.override. But the updated versions of Firefox doesn’t contain this option in their about:config by default. So you have to add this manually.

1. Type “about:config” in the URL
2. Now right-click on the list and select New>String
   

   

3. Then create a string with the name “network.security.ports.banned.override”

   

4. In value, you can add ports by these methods
   1-65535 (All Ports)
   87,88,89,1050 (for few ports with commas)

   

Restricted ports on Chrome:

1,       // tcpmux  7,       // echo  9,       // discard  11,      // systat  13,      // daytime  15,      // netstat  17,      // qotd  19,      // chargen  20,      // ftp data  21,      // ftp access  22,      // ssh  23,      // telnet  25,      // smtp  37,      // time  42,      // name  43,      // nicname  53,      // domain  77,      // priv-rjs  79,      // finger  87,      // ttylink  95,      // supdup  101,     // hostriame  102,     // iso-tsap  103,     // gppitnp  104,     // acr-nema  109,     // pop2  110,     // pop3  111,     // sunrpc  113,     // auth  115,     // sftp  117,     // uucp-path  119,     // nntp  123,     // NTP  135,     // loc-srv /epmap  139,     // netbios  143,     // imap2  179,     // BGP  389,     // ldap  427,     // SLP (Also used by Apple Filing Protocol)  465,     // smtp+ssl  512,     // print / exec  513,     // login  514,     // shell  515,     // printer  526,     // tempo  530,     // courier  531,     // chat  532,     // netnews  540,     // uucp  548,     // AFP (Apple Filing Protocol)  556,     // remotefs  563,     // nntp+ssl  587,     // stmp?  601,     // ??  636,     // ldap+ssl  993,     // ldap+ssl  995,     // pop3+ssl  2049,    // nfs  3659,    // apple-sasl / PasswordServer  4045,    // lockd  6000,    // X11  6665,    // Alternate IRC [Apple addition]  6666,    // Alternate IRC [Apple addition]  6667,    // Standard IRC [Apple addition]  6668,    // Alternate IRC [Apple addition]  6669,    // Alternate IRC [Apple addition]  6697,    // IRC + TLS

Restricted ports on Firefox:

1,       // tcpmux  7,       // echo  9,       // discard  11,      // systat  13,      // daytime  15,      // netstat  17,      // qotd  19,      // chargen  20,      // ftp data  21,      // ftp access  22,      // ssh  23,      // telnet  25,      // smtp  37,      // time  42,      // name  43,      // nicname  53,      // domain  77,      // priv-rjs  79,      // finger  87,      // ttylink  95,      // supdup  101,     // hostriame  102,     // iso-tsap  103,     // gppitnp  104,     // acr-nema  109,     // pop2  110,     // pop3  111,     // sunrpc  113,     // auth  115,     // sftp  117,     // uucp-path  119,     // nntp  123,     // NTP  135,     // loc-srv /epmap  139,     // netbios  143,     // imap2  179,     // BGP  389,     // ldap  465,     // smtp+ssl  512,     // print / exec  513,     // login  514,     // shell  515,     // printer  526,     // tempo  530,     // courier  531,     // chat  532,     // netnews  540,     // uucp  587,     // stmp?  601,     // ??  636,     // ldap+ssl  993,     // ldap+ssl  995,     // pop3+ssl  2049,    // nfs  3659,    // apple-sasl / PasswordServer  4045,    // lockd  6000,    // X11