Which ports are considered unsafe by Chrome?

Question

Some ports generate an error (ERR_UNSAFE_PORT) when browsing to them via Chrome (see this related question). Which ports are considered safe, and which are unsafe by default?

Answer 1

The following is a list of all of the 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
69,     // tftp
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
137,    // netbios
139,    // netbios
143,    // imap2
161,    // snmp
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)
554,    // rtsp
556,    // remotefs
563,    // nntp+ssl
587,    // smtp (rfc6409)
601,    // syslog-conn (rfc3195)
636,    // ldap+ssl
993,    // ldap+ssl
995,    // pop3+ssl
1719,   // h323gatestat
1720,   // h323hostcall
1723,   // pptp
2049,   // nfs
3659,   // apple-sasl / PasswordServer
4045,   // lockd
5060,   // sip
5061,   // sips
6000,   // X11
6566,   // sane-port
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
10080,  // Amanda

Source: Chrome source.

Answer 2

The reason it's called unsafe is not because it's unsafe to Chrome, it's because it's unsafe to those services, where an attacker may try to use Chrome as a proxy to attacking services on those ports. More explanation here:

http://jazzy.id.au/default/2012/08/23/why_does_chrome_consider_some_ports_unsafe.html

Answer 3

by default web services normally run on port 80 and SSL encrypted traffic runs on port 443 so these should be "safe" ports. This is typically known as "default ports" or "well known ports". "safe" seems to be a chrome-ism :)

"safe" is a bit meaningless though. If it runs on anouther port its more likely to be dodgy traffic, but just because its on port 80 dosent mean it wont install malware and etc on your pc.