372
Summary
- // typical exposure
- Anomalous (rarely legitimately open) — ulistproc is a legacy, effectively dormant mailing-list service with near-zero modern prevalence, so any open instance is anomalous and warrants investigation rather than routine exposure.
- // common applications
- ListProcessor Traffic on this port, if seen, is most likely associated with the legacy ListProcessor mailing-list daemon named in the IANA registry; no other software has been confirmed using it in current sources.
- // analyst note
- near-zero modern prevalence — treat any open 372/tcp as an anomaly signal and investigate rather than assume routine use.
- // if you see it open
- Effectively dormant on the modern internet - no CVEs or malware associations found in this pass. An open port 372 today is anomalous and should be investigated as a forgotten legacy ListProcessor instance, a misconfiguration, or non-standard use rather than assumed benign.
About port 372/tcp.
Port 372/tcp carries ulistproc, the IANA-registered name for ListProcessor, a legacy mailing-list management daemon; it has no place facing the public internet today, and any live listener should be treated as an anomaly rather than routine infrastructure.
IANA's registry lists 372/tcp and 372/udp as ulistproc, description "ListProcessor," assignee Anastasios Kotsikona. The Reference, Registration Date, and Modification Date columns are all blank — no RFC or standards document backs the assignment, and no date can be honestly attached to it.
ListProcessor (sometimes referenced as "ulistserv") appears to be an early mailing-list manager in the same family as LISTSERV and Majordomo, tools used to run BITNET- and early-internet-era discussion lists. Given that lineage, an early-to-mid-1990s origin is plausible, but no source in this pass confirms a specific date or software release.
Modern scan telemetry shows the port is effectively dormant: nmap-services records an open-frequency of 0.000000 for 372/tcp (not observed open in the scan corpus) and a negligible 0.000593 for 372/udp. No CVEs or malware associations turned up in this research pass.
- IANA assignment
ulistproc— "ListProcessor"; reference (blank); assignee Anastasios Kotsikona; dual-registered 372/tcp + 372/udp [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry-738- Range class
- well-known (0–1023) [Confirmed]
- Prevalence
- nmap-services open-frequency 372/tcp ≈ 0.000000 (not observed open); 372/udp ≈ 0.000593 (negligible) [Confirmed] — https://raw.githubusercontent.com/nmap/nmap/master/nmap-services
- Related ports
- 25/tcp (SMTP) as the general mail-delivery context for mailing-list software [Likely]
Primary use
legacy mailing-list management daemon (ListProcessor/ulistserv), analogous to LISTSERV/Majordomo
Other/unofficial uses
none identified this pass [Unknown]
Security implications
dormant/legacy port with no known CVEs or malware associations found; an open instance is anomalous and worth investigating [Unknown/Likely]
Typically seen on
no current sightings identified; historically, legacy mailing-list servers if any remain in operation [Unknown]
- Analyst note
- near-zero modern prevalence — treat any open 372/tcp as an anomaly signal and investigate rather than assume routine use.
About port 372/udp.
Port 372/udp is registered with IANA under the service name ulistproc, tied to the early-1990s ListProcessor (ListProc) mailing-list management daemon; no current or historical evidence of active deployment was found, so a host answering on this port should be treated as anomalous rather than as a legitimate public-facing service.
IANA's registry lists the description "ListProcessor," assignee Anastasios Kotsikonas (originally at Boston University; the software was later maintained and distributed by CREN), and dual TCP/UDP registration under the same service name. No RFC or other reference document is cited, and the registry records no registration date for the entry — consistent with many of IANA's oldest, undocumented assignments.
Beyond the bare registry entry, this research pass found no scanning telemetry, honeypot reports, security advisories, or community sightings (forums, blog posts, vendor documentation) referencing UDP/372. SpeedGuide.net's port page could not be reached (HTTP 403), and the port does not appear on Wikipedia's list of TCP/UDP port numbers; this is a coverage gap in the research, not a confirmed clean bill.
Given the age of the assignment and the complete absence of a modern usage footprint, port 372 should be treated as dormant or legacy. It carries no known malware association in the sources checked, but any observed traffic warrants investigation rather than an assumption of benign legacy mailing-list activity, since the software it names has shown no evident mainstream use in decades.
- IANA assignment
ulistproc— "ListProcessor"; reference (blank — no RFC cited in IANA registry); assignee Anastasios Kotsikonas; dual-registered 372/tcp + 372/udp [Confirmed] — https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml- Range class
- well-known (0–1023) [Confirmed]
- Prevalence
- no nmap-services open-frequency data located for this port in this pass [Unknown]
- Related ports
- none confirmed in this research pass [Unknown]
Primary use
historical service port for ListProcessor (ListProc), a mailing-list management daemon from the early-to-mid 1990s Unix era
Other/unofficial uses
none found in this research pass [Unknown]
Security implications
no scanning telemetry, advisories, or malware associations found; treat as dormant/legacy and investigate any observed traffic as anomalous [Unknown/Likely]
Typically seen on
legacy Unix hosts that formerly ran ListProcessor (ListProc), if any remain reachable — no current evidence of active deployment [Unknown]
- Analyst note
- registration date is not recorded by IANA for this entry; leave blank rather than inventing one [Confirmed — blank in registry]
Service assignments.
| Name | Protocol | Description | Open frequency |
|---|---|---|---|
| ulistserv | UDP | Unix Listserv | 0.06% |
| ulistserv | TCP | ulistproc | 0.00% |
Service assignments from the IANA Service Name and Transport Protocol Port Number Registry, with open-frequency data from nmap-services.