Port 2401CVS

**CVS (Concurrent Versions System)** is a legacy version control tool that enables multiple developers to collaborate on source code by tracking changes over time. CVS uses a client-server architecture, where clients communicate with a centralized CVS server, typically over port 2401, to commit updates, review revisions, and perform merges. Though largely supplanted by modern systems like Git and Mercurial, CVS still appears in some legacy environments..

transport
tcp

single transport

in transit
cleartext

payload readable on path

assignment
unofficial

used by convention

risk
4/10

caution

lookups
4,940

rank 926 of 993 · top 93%

Technical Details

what runs on :2401

Overview:

CVS (Concurrent Versions System) is an open-source, client-server revision control system widely used before the advent of distributed solutions like Git. It enables developers to keep track of software development history by maintaining versions of files and directories within a centralized repository.

Architecture and Protocol:

CVS uses a centralized model where developers check out working copies from a central server and then commit changes back. Communication between CVS clients and servers typically occurs over TCP port 2401, using a custom, plaintext-oriented protocol that negotiates commands and data transfers. Authentication is handled via mechanisms like pserver, ssh, or Kerberos depending on configuration.

Legacy and Integration:

CVS supports branching, tagging, and merging, albeit with limited capabilities compared to modern DVCS tools. It is often wrapped within network services for remote access. Despite its limitations — such as inefficient branching and lack of atomic commits — CVS persists in certain older projects and organizational workflows.

Security Information

exposure of :2401

risk score

4/ 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 0.1 below.

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

every listening transport is another surface to filter at the edge

security overview

Common vulnerabilities:

  • Unauthorized access via weak or misconfigured authentication (e.g., plaintext passwords with pserver).
  • Exposure of repository contents due to lack of encryption or access controls.
  • Vulnerabilities in CVS server implementations that could lead to remote code execution, denial of service, or information disclosure.

Common mitigations:

  • Use secure authentication mechanisms like SSH tunneling instead of plaintext pserver authentication.
  • Restrict network access to port 2401 through firewalls and network segmentation.
  • Regularly update and patch CVS server software to address known vulnerabilities.
  • Monitor CVS access logs for suspicious activity and enforce strong authentication and authorization policies.
  • Consider migrating to modern, more secure version control systems with improved encryption and fine-grained access control.

the 8 most looked-up other ports in file transfer — 114 ports carry that label.

risk mix of the 8 listed

  • caution100%

1 of 8 encrypted