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Port 90PointCast

**PointCast** was an early push technology service prominent in the late 1990s, which delivered personalized news and information to users' desktops over the internet, typically via a screensaver interface. It relied heavily on port 90 for communication, using both TCP and UDP protocols to transfer data streams and content updates..

inWeb ServicesStreaming
transport
tcp · udp

2 transports registered

in transit
cleartext

payload readable on path

assignment
unofficial

used by convention

risk
4/10

caution

lookups
9,441

rank 507 of 993 · top 51%

1 other service is registered on port 90. compare all 2 →

Technical Details

what runs on :90

Port 90 was utilized by PointCast, one of the pioneering webcasting platforms that leveraged 'push' technology to deliver live news feeds, stock tickers, and other customized web content. It employed both TCP and UDP depending on the type of data and the need for reliable versus fast delivery. Key to its operation was maintaining an open connection with the PointCast server infrastructure for updates.

Architecturally, PointCast functioned by acting as a screensaver which connected regularly over the internet, retrieving personalized content streams. This required the application to establish outbound connections on port 90, which was non-standard and largely unofficial compared to typical service ports. The system architecture made heavy use of HTTP-like communication layered over this port number, though it did not conform strictly to HTTP standards.

Today, port 90 is generally considered unassigned by IANA for any official purpose. Nevertheless, due to historic usage by PointCast and potentially other unofficial services, it might still be seen open or occasionally used in legacy settings or niche point solutions. Awareness of its background helps in interpreting network scans and legacy system behaviors.

Security Information

exposure of :90

risk score

4/ 10caution

worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.

web services averages 3.9 across 112 ports — this one sits 0.1 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

tcp · udp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

Common vulnerabilities:

  • Open port 90 may allow unauthorized communication channels or be exploited by malware imitating push services.
  • Since this port is unofficial, network security appliances might overlook non-standard traffic using it, posing a risk.
  • Lack of encryption historically associated with PointCast increases susceptibility to eavesdropping, data manipulation, and man-in-the-middle attacks.

Common mitigation strategies:

  • Block or restrict inbound and outbound traffic on port 90 unless explicitly required.
  • Monitor network activity for unusual or unauthorized communications over port 90.
  • Employ firewall rules to prevent exploitation of legacy services.
  • Use encrypted alternatives and more modern content delivery protocols that incorporate authentication and encryption.
  • Regularly scan and audit network ports, especially non-standard ones, to reduce attack surface.

Related Ports

all 112 in web services →

the 8 most looked-up other ports in web services — 112 ports carry that label.

portservicerisk
:8888Sun Answerbook & Alt HTTPcaution
:8000Intel Remote Desktop / Alternate HTTP Portsafe
:8888NewsEDGEcaution
:8888HTTP Alternative Portcaution
:8888GNUmp3d Streaming HTTPcaution
:9080Groove RPCcaution
:8881Atlasz Secure Servercaution
:80HTTPcaution

risk mix of the 8 listed

  • safe13%
  • caution88%

0 of 8 encrypted