477
Summary
- // typical exposure
- Anomalous (rarely legitimately open) — No confirmed legitimate protocol or software is documented for this port, its nmap-services TCP open-frequency reads 0, and IANA's own entry carries no description — an open 477/tcp has no expected legitimate reason to be reachable, let alone internet-facing.
- // analyst note
- An open 477/tcp has no confirmed legitimate service behind it as of this research; treat as anomalous and investigate rather than assume routine use.
- // if you see it open
- No confirmed CVE or malware/trojan association found as of an August 2026 search; auditmypc.com's port-477 page carries no Virus/Trojan verdict section. Because no legitimate deployment or vendor use is documented, an open 477/tcp is anomalous and worth investigating rather than treating as routine.
About port 477/tcp.
Port 477/tcp carries a service IANA lists only under the bare name ss7ns; it should be treated as internal/anomalous rather than something to expose to the public internet, since no vendor documentation or known deployment confirms what actually runs there.
IANA's Service Name and Transport Protocol Port Number Registry assigns 477 (both tcp and udp) the name ss7ns with contact Jean-Michel Ursch, but the description field is blank and no RFC or other reference is cited. The name suggests some link to SS7 (Signaling System No. 7) telephony signaling, but IANA's registry text does not spell out a protocol, and no independent source confirms that reading.
No web search turned up vendor documentation, blog posts, forum threads, or software release notes naming a specific application that uses TCP port 477. Generic port-lookup directory sites repeat the same bare ss7ns label without adding detail, and several of those sites could not even be reached during this research pass (403 responses, connection errors, TLS failures), so they are not relied on for any claim here.
auditmypc.com's port-477 page was reachable and carries no Virus/Trojan verdict section for this port, which is evidence against a known malware association, though the absence of a listing is not strong proof of anything either way.
- IANA assignment
ss7ns— description blank; reference blank; contact Jean-Michel Ursch; registered on both TCP and UDP [Confirmed] — https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?page=9- Range class
- system/well-known (0–1023) [Confirmed] — IANA registry range convention
- Prevalence
- nmap-services open-frequency 477/tcp = 0; 477/udp = 0.000626 [Confirmed] — this site's own enrichment records site's own tooling
- Related ports
- 477/udp (same IANA
ss7nsname, dual-registered) [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry
Primary use
Unknown — IANA lists only the bare name ss7ns with no protocol description; a link to SS7 telephony signaling is suggested by the name but not confirmed by any source
Other/unofficial uses
None found as of an August 2026 web search pass; no vendor docs, blog posts, or forum threads named a specific application using this port [Unknown]
Security implications
no confirmed malware/CVE association; treated as anomalous due to the near-total absence of legitimate documented use
Typically seen on
Unknown — no deployment pattern documented [Unknown]
- Analyst note
- An open 477/tcp has no confirmed legitimate service behind it as of this research; treat as anomalous and investigate rather than assume routine use.
About port 477/udp.
Port 477/udp is IANA-registered under the name ss7ns; no protocol document defines it and no software is confirmed to run on it in practice, so it should be treated as internal-only/anomalous rather than exposed to the public internet.
The IANA Service Name and Transport Protocol Port Number Registry lists ss7ns identically for both 477/tcp and 477/udp, assignee Jean-Michel Ursch, with a blank Reference field — no RFC or other specification is cited, and none was found elsewhere. IANA's Description column simply repeats the service name ss7ns rather than expanding it; the name suggests some link to SS7 (Signaling System No. 7) telephony signaling, but that reading is an inference from the name string, not an IANA description, and no independent source confirms it.
A targeted search for real-world deployments — vendor documentation, blog posts, and forum or support threads — turned up nothing beyond generic port-lookup mirror sites that simply restate the IANA label without naming any client or server software. No CVE tied specifically to port 477 is recorded in the NVD as of an August 2026 search.
Measured open-frequency from the repository's nmap-services-derived dataset is low: 477/udp sits at 0.000626 (~0.06%) and 477/tcp at exactly 0 (sampled, not observed open) in this site's own tooling. Combined with the absence of any documented protocol or known deployed software, an open 477/udp is unusual and worth investigating rather than assuming benign.
- IANA assignment
ss7ns— Description column readsss7ns(repeats the service name, not an expanded description); reference (blank); assignee Jean-Michel Ursch; dual-registered 477/tcp + 477/udp — the IANA Service Name and Transport Protocol Port Number Registry ss7ns 477/udp- Range class
- well-known (0–1023) [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry ss7ns 477/udp
- Prevalence
- nmap-services open-frequency 477/udp = 0.000626 (~0.06%); 477/tcp = 0 (sampled, not observed open) [Confirmed] — this site's own tooling
- Related ports
- none specifically documented as related; contrast other SS7-adjacent/telco signaling services which use distinct, separately registered ports
Primary use
registered by IANA as ss7ns, description column identical to the name; no RFC or protocol specification is published
Other/unofficial uses
none found; no vendor docs, blog posts, or forum threads report software using this port as of an August 2026 search
Security implications
undocumented protocol, no confirmed real-world software, near-zero measured prevalence; no CVE found tied to this port as of an August 2026 search; no malware/trojan association established in the sources checked [Likely]
Typically seen on
not established — no host type or deployment context found [Unknown]
- Analyst note
- an open 477/udp is statistically rare and has no documented protocol behind it — treat as an anomaly to investigate rather than a normal service.
Service assignments.
| Name | Protocol | Description | Open frequency |
|---|---|---|---|
| ss7ns | UDP | — | 0.06% |
| ss7ns | TCP | — | 0.00% |
Service assignments from the IANA Service Name and Transport Protocol Port Number Registry, with open-frequency data from nmap-services.