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Port 750Kerberos IV

Kerberos version IV is an authentication protocol primarily used to verify the identities of clients and servers in distributed network environments. Operating over UDP port 750, Kerberos IV employs a ticket-based system to securely authenticate users without transmitting passwords in plaintext, enhancing overall security. Though widely influential, this older version has been mostly superseded by Kerberos V due to enhanced features and security improvements..

inSecurityNetwork ServicesSystem
transport
udp

single transport

in transit
cleartext

payload readable on path

assignment
official

registered with iana

risk
2/10

safe

lookups
8,009

rank 635 of 993 · top 64%

2 other services are registered on port 750. compare all 3 →

Technical Details

what runs on :750

  • Kerberos IV Overview: Kerberos IV is a network authentication protocol designed to provide secure identity verification over insecure networks. Developed at MIT, it uses symmetric key cryptography and relies on a trusted third-party authority known as the Key Distribution Center (KDC) to issue time-sensitive tickets, allowing access without repeatedly transmitting a user's password.

  • Operation and Ticketing: When a user initially authenticates to the network, they request a Ticket Granting Ticket (TGT) from the Authentication Server (AS). This TGT is encrypted using the user's password-derived key, enabling access to further services by obtaining service-specific tickets from the Ticket Granting Server (TGS) without re-entering credentials.

  • Limitations and Ecosystem Role: Kerberos IV became foundational in secure network authentication but has limitations including less robust encryption algorithms and lack of support for modern cryptographic practices. Due to these constraints and vulnerability disclosures, it has been largely replaced by Kerberos V. Nonetheless, understanding Kerberos IV remains essential for legacy system support and security analysis.

Security Information

exposure of :750

risk score

2/ 10safe

routine exposure. this port is rarely the way in on its own — keep it patched and logged and move on.

security averages 3.8 across 216 ports — this one sits 1.8 below.

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

udp

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

security overview

  • Common Vulnerabilities:

    • Use of deprecated encryption algorithms susceptible to cryptanalysis.
    • Potential replay attacks if ticket lifetimes are not tightly controlled.
    • Lack of support for modern cryptographic standards, making it vulnerable to sophisticated attacks.
    • Since UDP is connectionless, Kerberos IV traffic might be more susceptible to spoofing or packet injection.

  • Mitigations:

    • Upgrade to Kerberos version V, which addresses many security gaps.
    • Strictly control the validity periods of tickets to minimize replay risks.
    • Employ secure network segmentation and monitoring to detect anomalous Kerberos traffic.
    • Use packet filtering and robust firewall rules to restrict unnecessary exposure of port 750.
    • Whenever possible, use encrypted tunnels (e.g., IPSec or VPN) to add a security layer for legacy Kerberos IV implementations.

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risk mix of the 8 listed

  • caution100%

3 of 8 encrypted