Port 17Quote of the Day
The Quote of the Day (QOTD) protocol is a simple Internet service that provides a short message when a client connects to it. Traditionally, it was often used for demonstrating connectivity, server responsiveness, or simply to display inspirational or humorous quotes. While historically popular for testing and fun, the protocol has largely fallen out of everyday practical use and is now mostly of historical interest or used in controlled environments..
- transport
- tcp · udp
- in transit
- cleartext
- assignment
- official
- risk
- 4/10
- lookups
- 6,973
2 transports registered
payload readable on path
registered with iana
caution
rank 733 of 993 · top 74%
Technical Details
what runs on :17The Quote of the Day (QOTD) protocol is defined in RFC 865 and operates over TCP and UDP port 17. When a client connects to a QOTD server, the server sends a short ASCII message containing a quote or phrase, then closes the connection. Because of its simplicity, no commands or additional client input are required: the act of connecting triggers the quote delivery.
Due to its minimal functionality, implementation of a QOTD server is straightforward. Many servers cycle through a database of quotes or generate random phrases dynamically. The protocol is stateless and requires no authentication, session management, or complex parsing—making it a lightweight method to test connectivity or display server status messages.
QOTD mainly existed as a demonstration or test service, helping system administrators verify network and server operation in early Internet days. Nowadays, it is uncommon to find active QOTD services on production systems, and the protocol is largely considered obsolete except in certain educational or legacy testing setups.
Security Information
exposure of :17risk score
4/ 10caution
worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.
network services averages 3.9 across 604 ports — this one sits 0.1 above.
in transit
cleartext
credentials and payloads are readable by anyone on path
assignment
official
registered with iana for this service — scanners fingerprint it by number
reachable over
tcp · udp
udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite
security overview
Common Vulnerabilities:
- Open QOTD services can be abused for reflective Distributed Denial of Service (DDoS) amplification attacks, as the server responds unconditionally to incoming requests.
- Lack of authentication allows information leakage if sensitive or custom data is stored in the quote database.
- Publicly exposed QOTD services can be leveraged during reconnaissance phases of attacks, identifying legacy systems or misconfigurations.
Common Mitigations:
- Disable QOTD services on all internet-facing systems unless required for specific internal uses.
- Use access control lists (ACLs) or firewall rules to restrict port 17 from external access.
- Implement logging and monitoring to detect unauthorized requests.
- Remove or sanitize quote content that might reveal internal or sensitive details.
- Consider disabling or uninstalling QOTD daemon entirely, as it is rarely needed today.
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| :3128 | Tatsoft Default HTTP Proxy | TCP | Web Services | caution | 46.8k |
risk mix of the 8 listed
- caution100%
0 of 8 encrypted