Port 903VMware Remote Console

VMware Remote Console (VMRC) enables users to remotely access and manage virtual machines hosted on VMware infrastructure, providing full console access with mouse and keyboard control for administration and troubleshooting purposes..

transport
tcp

single transport

in transit
cleartext

payload readable on path

assignment
unofficial

used by convention

risk
4/10

caution

lookups
6,328

rank 798 of 993 · top 80%

Technical Details

what runs on :903

VMware Remote Console (VMRC) functions as a standalone application or browser plugin allowing direct console access to virtual machines (VMs) managed by VMware products like vSphere, ESXi, or vCenter Server. Utilizing port 903 by default over TCP, VMRC facilitates the transmission of display, input, and control commands between the client and the virtual machine’s console, enabling seamless interaction as if physically present at the VM.

The port supports the VMware Console protocol within the broader VMware VNC service to establish sessions, handle authentication, and maintain state consistency during virtual machine management scenarios. Unlike remote protocol alternatives such as RDP or SSH, VMRC provides direct hypervisor-level access, often required for tasks like OS installation, BIOS configuration, or recovery when higher-level network services are unavailable within the VM.

In VMware environments, communication over port 903 is generally initiated from the VMRC client, connecting directly to the ESXi host or via vCenter Server. Network considerations should include firewall rules accommodating this port to ensure connectivity, while also considering segmentation to limit exposure.

Security Information

exposure of :903

risk score

4/ 10caution

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

remote access averages 4.0 across 110 ports — this one sits level with it.

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 due to improper authentication controls or weak credentials
  • Man-in-the-middle (MitM) attacks if traffic is unencrypted
  • Port exposure in public networks increasing brute force risks
  • Exploitation of outdated VMware services to gain unauthorized console access

Common mitigations:

  • Enforce strong multi-factor authentication for console access
  • Restrict port 903 exposure to trusted IP ranges only via firewalls
  • Enable encryption/tunnel the VMRC communication via secure channels (e.g., VPN, SSH port forwarding)
  • Keep VMware infrastructure components patched to the latest security updates
  • Monitor console access logs for unusual activity and configure alerts on anomalous use

the 8 most looked-up other ports in remote access — 110 ports carry that label.

risk mix of the 8 listed

  • safe13%
  • caution88%

0 of 8 encrypted