GEN:SID 1:2189
Message BAD-TRAFFIC IP Proto 103 PIM
Summary This event is generated when a suspicious packet using an unusual
protocol is sent to a router.
Impact Denial of Service (DoS).
Detailed Information A vulnerability exists in multiple Cisco IOS versions such that a Denial
of Service condition can be issued against a device by sending multiple
packets using IP protocols 53, 55, 77 and 103 directly to that device.

Cisco IOS processes these packets and under certain circumstances, can
be made to incorrectly flag an input interface as being full.
Affected Systems Multiple versions of Cisco IOS.
Attack Scenarios An attacker may send a large number of IP packets using one of the
protocols 53, 55, 77 or 103 directly to a router. Exploit code exists.
Ease of Attack Simple. Expoit code exists.
Corrective Action Upgrade to the latest non-affected version of the software.

Apply the appropriate vendor supplied patches.
Additional References  
Rule References bugtraq: 8211
cve: 2003-0567