The STP protocol implementation in Linux 2.4.x does not properly verify certain lengths, which could allow attackers to cause a denial of service.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A384
http://www.redhat.com/support/errata/RHSA-2003-239.html
http://www.redhat.com/support/errata/RHSA-2003-238.html