Vulnerability Note VU#644886

Ethereal fails to properly parse NetFlow UDP packets with an overly large template_entry count

Original Release date: 24 Mar 2004 | Last revised: 25 Mar 2004

Overview

Ethereal fails to properly parse v9_template structures in NetFlow UDP packets with an overly large template_entry count. This could allow an attacker to execute arbitrary code.

Description

Ethereal is a network traffic analysis package. It includes the ability to decode packets containing NetFlow data. There is a buffer overflow vulnerability in the way the NetFlow v9 dissector parses v9_template structures in a NetFlow UDP packet. A remote, unauthenticated attacker could exploit this vulnerability by sending a NetFlow UDP packet containing an overly large template_entry count which could allow for arbitrary code execution.

Impact

A remote, unauthenticated attacker could execute arbitrary code on the vulnerable system.

Solution

Upgrade

Upgrade to version 0.10.3 or later.

Note: Ethereal is considered BETA software at this time.


Disable Dissector

If you are unable to upgrade to version 0.10.3 or later, you can disable the NetFlow protocol dissector by performing the following actions in Ethereal:

(for Ethereal versions 0.9.x)

    1) Select Edit->Protocols
    2) Deselect the NetFlow protocol dissector from the list

(for Ethereal versions 0.10.x)
    1) Select Analyze->Enabled Protocols
    2) Disable the CFLOW (Cisco NetFlow) protocol dissector from the list by unchecking its "Status" checkbox

However, it is strongly encouraged to upgrade to version 0.10.3 or later.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
EtherealAffected-24 Mar 2004
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

References

Credit

Ethereal credits Stefan Esser for reporting this vulnerability.

This document was written by Damon Morda.

Other Information

  • CVE IDs: CAN-2004-0176
  • Date Public: 22 Mar 2004
  • Date First Published: 24 Mar 2004
  • Date Last Updated: 25 Mar 2004
  • Severity Metric: 9.82
  • Document Revision: 25

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