Port 9303D-Link SharePort
Port 9303 is typically associated with D-Link SharePort services, enabling network sharing of USB storage devices and multifunction printers across local networks on D-Link routers. This port facilitates file sharing and printer access by bridging these USB devices to multiple clients seamlessly..
- transport
- udp
- in transit
- cleartext
- assignment
- unofficial
- risk
- 5/10
- lookups
- 7,958
single transport
payload readable on path
used by convention
caution
rank 641 of 993 · top 65%
Technical Details
what runs on :9303D-Link SharePort technology provides a means to connect USB storage devices and multifunction printers directly to D-Link network devices, allowing users on the LAN to access shared content or printers without connecting them via dedicated print or file servers.
Primarily, the service communicates over UDP port 9303, broadcasting availability and managing discovery of connected devices. Client software on users' machines listens on this port to identify attached printers or storage, then establishes a peer-to-peer session with the router. The communication protocol involves lightweight discovery and file management commands, optimized for low latency on local networks.
Because this service is specific to D-Link hardware, the implementation details can vary across device models and firmware versions. Typically, it does not expose the devices beyond the LAN but facilitates internal sharing to improve convenience and reduce reliance on dedicated hardware servers within small networks.
Security Information
exposure of :9303risk score
5/ 10caution
worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.
file transfer averages 4.1 across 114 ports — this one sits 0.9 above.
in transit
cleartext
credentials and payloads are readable by anyone on path
assignment
unofficial
used by convention, not registered — what answers here varies by deployment
reachable over
udp
udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite
security overview
Common Vulnerabilities
- Since SharePort often uses unauthenticated broadcast messages, it can be susceptible to misuse by unauthorized users on the same network, potentially allowing access to files or print jobs.
- In some firmwares, insufficient input validation can expose buffer overflow risks or arbitrary code execution if crafted packets are received.
- Lack of encryption or authentication increases the risk of eavesdropping or man-in-the-middle attacks, especially if the LAN is compromised.
Common Mitigations
- Restrict network segment access via VLANs or firewall rules to trusted clients.
- Update router firmware regularly, as D-Link periodically releases patches addressing security vulnerabilities.
- Disable SharePort services if not in use, minimizing attack surface.
- Use network segmentation and strong Wi-Fi security protocols (e.g., WPA3) to limit exposure.
- Monitor device logs for unusual device discovery or access patterns that may indicate abuse.
Related Ports
the 8 most looked-up other ports in file transfer — 114 ports carry that label.
| port | service | risk | |||
|---|---|---|---|---|---|
| :9080 | Groove RPC | TCPUDP | Web Services | caution | 70.8k |
| :17500 | Dropbox LAN Sync | TCPUDP | File Transfer | caution | 43.7k |
| :548 | Apple Filing Protocol | TCP | File Transfer | caution | 36.8k |
| :7000 | Vuze HTTPS Tracker | TCPtls | Security | caution | 28.9k |
| :1337 | PowerFolder P2P | TCP | Security | caution | 27.1k |
| :9001 | SharePoint Authoring | Web Services | caution | 26.3k | |
| :8080 | FilePhile Relay | UDP | File Transfer | caution | 25.6k |
| :1337 | WASTE Encrypted Sharing | TCP | Security | caution | 22.9k |
risk mix of the 8 listed
- caution100%
1 of 8 encrypted