308
Summary
- // typical exposure
- Restricted (trusted networks only) — It is a proprietary NovaStor backup-agent service, not designed for public reach, with an undocumented wire protocol — legitimate use should stay confined to trusted backup infrastructure rather than the open internet.
- // analyst note
- An open 308/tcp is unusual and obscure enough that its context (is a NovaStor backup product actually installed?) should be confirmed before assuming legitimacy; no known backdoor/malware use, but the undocumented protocol means it can't be vetted from public sources.
- // if you see it open
- No RFC or open specification is cited by IANA, so the on-wire protocol is not independently auditable from public sources. No malware, trojan-port, or public abuse reporting was found associated with 308/tcp (checked Trend Micro trojan-port docs, Gary Kessler's bad-ports list, community suspicious-port lists) as of 2026-07-18 — a sourced absence, not a safety guarantee. It is unclear whether current NovaStor product versions still bind this port; treat as possibly legacy.
About port 308/tcp.
Port 308/tcp carries NovaStor Backup's proprietary agent service, registered with IANA as novastorbakcup; it is not a service designed for public reach, so it should stay restricted to trusted backup infrastructure rather than sitting open to the internet.
IANA registers 308 identically on both tcp and udp as novastorbakcup / "Novastor Backup," with assignee and contact both listed as [Brian_Dickman]. The Registration Date, Modification Date, Reference, Service Code, and Assignment Notes columns are all blank in the registry — reported here as Unknown rather than guessed.
No RFC or public protocol specification accompanies the IANA entry, so the wire protocol NovaStor's agent speaks on this port is not independently documented in an open standard. The current-day product binding is also uncertain: NovaStor's backup lineage (NovaBACKUP / NovaStor DataCenter) is the likely user, but no modern vendor documentation was found confirming which shipping versions still use port 308 today.
No malware, trojan-port, or public abuse reporting was found associated with 308/tcp across the sources checked (Trend Micro's trojan-port list, Gary Kessler's bad-ports list, community suspicious-port lists). That absence is a sourced negative finding, not a guarantee of safety, especially for a port this rarely discussed in security literature.
- IANA assignment
novastorbakcup— "Novastor Backup"; reference (blank — no RFC cited); assignee/contact [Brian_Dickman]; dual-registered 308/tcp + 308/udp [Confirmed] — local cached IANA registry CSV, rows 627–628; corroborated at https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=308- Range class
- well-known (0–1023) [Confirmed]
- Prevalence
- Unknown — no nmap-services or scan-telemetry source consulted this cycle
- Related ports
- Unknown — no related-port cluster identified this cycle
Primary use
proprietary agent/service port for NovaStor's backup software (NovaBACKUP / NovaStor DataCenter family); no RFC-documented protocol
Other/unofficial uses
Unknown — no independent third-party documentation found this cycle
Security implications
no RFC/public spec to audit; no malware/trojan-port association found; unclear which current NovaStor product versions still bind it, so treat as likely legacy pending confirmation
Typically seen on
NovaStor backup software hosts (agent or management console) on internal/trusted backup networks [Likely]
- Analyst note
- An open 308/tcp is unusual and obscure enough that its context (is a NovaStor backup product actually installed?) should be confirmed before assuming legitimacy; no known backdoor/malware use, but the undocumented protocol means it can't be vetted from public sources.
About port 308/udp.
Port 308/udp is registered to NovaStor's backup software (novastorbakcup); it should stay internal to trusted networks rather than be exposed to the public internet.
IANA lists 308 as novastorbakcup ("Novastor Backup"), with a matching entry on 308/tcp (dual registration) and assignee/contact [Brian_Dickman]. The registry entry carries no RFC reference and no listed registration or modification date — both fields are legitimately blank rather than omitted by this write-up.
Current NovaStor product documentation, specifically the NovaStor xSP datasheet, lists port 308 as a port that must be open (direction configurable) for the product's agent/console communication. This is consistent with, though not a verbatim restatement of, the original IANA assignment, and ties the port to NovaStor's ongoing NovaBACKUP / DataCenter / xSP product line rather than a historical-only use.
No independently verifiable data was found on how many hosts expose 308/udp to the public internet, or on any documented scanning or abuse trend specific to this port. Generic port-list mirror sites only restate the IANA assignment and add no security context, so they were not used as a source for exposure claims; real-world exposure prevalence is Unknown rather than inferred.
- IANA assignment
novastorbakcup— "Novastor Backup"; reference (blank — no RFC cited in IANA registry); assignee[Brian_Dickman]; dual-registered 308/tcp + 308/udp [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry- Range class
- well-known (0–1023) [Confirmed]
- Prevalence
- not independently verified; no nmap-services or scan-engine data available for this port [Unknown]
- Related ports
- 308/tcp (dual IANA registration, same service
novastorbakcup) [Confirmed]
Primary use
NovaStor backup software agent/console communication (NovaBACKUP / NovaStor DataCenter / xSP)
Other/unofficial uses
none independently documented beyond the primary vendor use [Unknown]
Security implications
vendor requires the port open for xSP agent/console traffic; no documented CVEs or abuse trend found; treat unexpected public exposure as worth investigating
Typically seen on
hosts running NovaStor NovaBACKUP / DataCenter / xSP backup software
- Analyst note
- registry assignment and current vendor documentation both point to a legitimate backup-software channel; keep it restricted to the backup network segment rather than internet-facing.
Service assignments.
| Name | Protocol | Description | Open frequency |
|---|---|---|---|
| novastorbakcup | UDP | novastor backup | 0.03% |
| novastorbakcup | TCP | novastor backup | 0.00% |
Service assignments from the IANA Service Name and Transport Protocol Port Number Registry, with open-frequency data from nmap-services.