124
Summary
- // if you see it open
- No CVE/NVD or malware/exploit association found for 124/tcp in this pass, and it does not appear in mainstream commonly-attacked-ports references (SANS ISC, Tenable, Netwrix). Low-profile legacy port. Because low-numbered legacy ports are occasionally repurposed by unrelated or custom software, a live host with 124/tcp or 124/udp open should be identified by inspecting the actual listening service rather than assumed to be ANSA REX Trader.
- // analyst note
- An open port 124 is uncommon and its registered use is obsolete — verify the real service by inspection; do not assume the historical ANSA trader.
About port 124/tcp.
Port 124/tcp is registered with IANA as ansatrader with the description "ANSA REX Trader," assignee and contact Nicola J. Howarth, and a blank reference field; the assignment is dual-registered identically on 124/tcp and 124/udp. The registry shows no registration or modification date for this legacy entry, so no date is recorded here rather than an invented one. The name refers to the "trader" component of ANSAware, an early-1990s distributed-computing and object-broker platform developed by APM Ltd under the ANSA (Advanced Networked Systems Architecture) project — an effort contemporaneous with, and conceptually a predecessor to, CORBA-style architectures. In that model the trader mediated the lookup of service interfaces offered by ANSAware servers, and the platform was ported to environments such as SunOS, HP-UX, VMS, and MS-DOS. For a present-day analyst the practical point is that this is effectively an obsolete assignment: ANSAware is a defunct research-era platform with no actively maintained modern implementation documented on this port. No CVE, NVD, or malware/exploit association was found for 124/tcp in this pass, and it does not appear in mainstream "commonly attacked ports" references (SANS ISC, Tenable, Netwrix). Because low-numbered legacy ports are sometimes repurposed by unrelated or custom software, a live host observed with 124/tcp (or 124/udp) open should be identified by inspecting the actual listening service rather than assumed to be running the historical ANSA REX Trader.
- IANA assignment
ansatrader— "ANSA REX Trader"; reference (blank — no RFC cited in IANA registry); assignee/contact Nicola J. Howarth; dual-registered 124/tcp + 124/udp [Confirmed] — IANA Service Name and Transport Protocol Port Number Registry (the IANA Service Name and Transport Protocol Port Number Registry line 317; 124/udp line 318); https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=124- Range class
- well-known (0–1023) [Confirmed]
- Registration/modification date
- Unknown — blank in the IANA registry CSV and not displayed in the live IANA table for this legacy entry; not fabricated [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry line 317 (Registration Date / Modification Date columns blank)
- IANA reference (RFC)
- blank — no RFC is cited for this assignment; left blank per no-fabrication rule [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry line 317 (Reference column blank)
- Related ports
- contrast with modern service-discovery/object-broker mechanisms; dual-registered sibling 124/udp
Primary use
the "trader" component of ANSAware, an early-1990s distributed-computing/object-broker platform from APM Ltd's ANSA project (conceptual predecessor to CORBA), historically ported to SunOS, HP-UX, VMS, and MS-DOS [Likely] — secondary port-reference sources summarizing ANSA project documentation; https://www.speedguide.net/port.php?port=124 and http://www.t1shopper.com/tools/port-number/124/ (not verified against a primary ANSA spec in this pass)
Common software today
Unknown / effectively obsolete — no actively maintained modern implementation documented on this port; ANSAware is defunct [Unknown]
Security implications
no CVE/NVD or malware/exploit association found for 124/tcp; not present in mainstream commonly-attacked-ports lists (SANS ISC, Tenable, Netwrix); low-profile legacy port
Typically seen on
rarely seen open; treat any live 124/tcp or 124/udp as unusual and identify the actual listening service rather than assuming ANSA REX Trader
- Analyst note
- An open port 124 is uncommon and its registered use is obsolete — verify the real service by inspection; do not assume the historical ANSA trader.
About port 124/udp.
Port 124/udp is registered with IANA as ansatrader with the description "ANSA REX Trader," assigned to Nicola J. Howarth and dual-registered on both TCP and UDP under the same service name. The IANA reference field is blank — no RFC or protocol specification is cited in the registry, and no independent wire-protocol document could be located. The name traces to ANSA (Advanced Network Systems Architecture), a distributed-systems research platform developed by APM Ltd. in Cambridge, UK, during the early-to-mid 1990s; ANSA was a precursor to CORBA-style object middleware, and "REX Trader" appears to reference the trader (broker/lookup) service component of that architecture — a directory that lets distributed objects find one another by service type. That association is contextual naming only and is not confirmed against an authoritative protocol spec, so it should not be presented as documented behavior. For an analyst, port 124 is effectively a dormant/legacy well-known registration: no current or historical software implementing an ansatrader service was identified, there is no port-124-specific scanning telemetry, CVE, or security advisory in indexed sources, and third-party port databases (SpeedGuide, t1shopper, adminsub.net, auditmypc) merely republish the same bare IANA entry without additional detail. Treat a responsive port 124 as unusual and worth investigating rather than as a recognizable modern service; do not fabricate usage, exposure statistics, or vulnerabilities for it.
- IANA assignment
ansatrader— "ANSA REX Trader"; reference (blank — no RFC cited in IANA registry); assignee Nicola J. Howarth; dual-registered 124/tcp + 124/udp [Confirmed] — IANA Service Name and Transport Protocol Port Number Registry (https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=124); cached registry CSV (the IANA Service Name and Transport Protocol Port Number Registry, line 318)- Range class
- well-known (0–1023) [Confirmed]
- IANA reference/RFC
- blank — none cited in the registry [Confirmed] — IANA registry
- Registration/modification dates
- Unknown — the Registration Date and Modification Date columns are blank in the source registry (not invented) [Unknown] — cached registry CSV / IANA registry
- Related ports
- 124/tcp (same
ansatraderregistration, same assignee)
Primary use
named registration for the ANSA "REX Trader" service (a trader/broker directory component of the ANSA distributed-systems architecture, APM Ltd., Cambridge UK, early-1990s); no protocol spec or wire-format document located [Likely] — inferred from the service name and ANSA project history; IANA registry (https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=124)
Common software
none identified — no current or historical daemon, library, or product implementing ansatrader on port 124 was found
Exposure / scanning
Unknown — no Shodan/Censys-style exposure data, CVEs, or scanning writeups specific to port 124 (TCP or UDP) were found as of 2026-07-02 PDT [Unknown]
Other/unofficial uses
none documented; as with any well-known port it could be repurposed informally on a given network, but no such pattern was found
- Analyst note
- Effectively a dormant/legacy well-known registration. A responsive port 124 is unusual; investigate it as an anomaly rather than assuming a known service. Do not fabricate usage, CVEs, or scan statistics.
Service assignments.
| Name | Protocol | Description | Open frequency |
|---|---|---|---|
| ansatrader | UDP | ANSA REX Trader | 0.06% |
| ansatrader | TCP | ANSA REX Trader | 0.00% |
Service assignments from the IANA Service Name and Transport Protocol Port Number Registry, with open-frequency data from nmap-services.