Vulnerability Note VU#181721

Alcatel Operating System (AOS) does not require a password for accessing the telnet server

Original Release date: 20 Nov 2002 | Last revised: 21 Nov 2002


The OmniSwitch 7700/7800 running Alcatel Operating System (AOS) version 5.1.1 has TCP port 6778 listening as a telnet server. This gives anyone access to the OmniSwitch's Vx-Works operating system without requiring a password.


During an NMAP audit of the AOS 5.1.1 code that runs on the Alcatel OmniSwitch 7700/7800 LAN switches, it was determined a telnet server was listening on TCP port number 6778. This was used during development to access the Wind River Vx-Works operating system. Due to an oversight, this access was not removed prior to product release.


Anyone running NMAP on AOS 5.1.1 will see port 6778 listening. The attacker is able to telnet to the port and access the OmniSwitch operating system without a password. This backdoor compromises the entire system.


1) Immediate - create an ACL blocking all access to TCP port 6778.
2) Short-term - Alcatel Customer Support has updated code that removes this backdoor. This fix is part of AOS 5.1.1.R02 and AOS 5.1.1.R03. Contact Customer Support for this updated code.
3) Permanent - the generally available AOS code--the code that ships with each OmniSwitch--will have this vulnerability removed as of AOS 5.1.3.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
AlcatelAffected-20 Nov 2002
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



Thanks to Alcatel for reporting this vulnerability.

This document was written by Alcatel's Olivier Paridaens and Jeff Hayes. This document was published by Ian A. Finlay.

Other Information

  • CVE IDs: CAN-2002-1272
  • CERT Advisory: CA-2002-32
  • Date Public: 20 Nov 2002
  • Date First Published: 20 Nov 2002
  • Date Last Updated: 21 Nov 2002
  • Severity Metric: 49.50
  • Document Revision: 20


If you have feedback, comments, or additional information about this vulnerability, please send us email.