The Nokia router must be configured to drop all fragmented Internet Control Message Protocol (ICMP) packets destined to itself.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-283891 | NOKI-RT-000760 | SV-283891r1203922_rule | CCI-001097 | medium |
| Description | ||||
| Fragmented ICMP packets can be generated by hackers for denial-of-service attacks such as Ping O' Death and Teardrop. It is imperative that all fragmented ICMP packets are dropped. | ||||
| STIG | Date | |||
| Nokia Service Router OS 25.x Router Security Technical Implementation Guide | 2026-06-15 | |||
Details
Check Text (C-283891r1203922_chk)
Review the access control list (ACL) or filter for the router receive path.
Review the CPM filter to verify the router is configured to drop all fragmented ICMP packets destined to itself using the example below:
- show system security cpm-filter ip-filter entry 10
CPM IP Filter Entry
Entry Id : 10
Description : (Not Specified)
-------------------------------------------------------------------------------
Filter Entry Match Criteria :
-------------------------------------------------------------------------------
Log Id : n/a
Src. IP : n/a
Src. Port : n/a
Dst. IP : n/a
Dest. Port : n/a
Protocol : icmp Dscp : Undefined
ICMP Type : Undefined ICMP Code : Undefined
Fragment : True Option-present : Off
IP-Option : n/a Multiple Option : Off
TCP-syn : Off TCP-ack : Off
Action : Drop
Match Router ID : n/a
Dropped pkts : 0 Forwarded pkts : 0
If the router is not configured with a receive-path filter to drop all fragmented ICMP packets, this is a finding.
Fix Text (F-88361r1203921_fix)
Configure the CPM filter to drop all fragmented ICMP packets destined to itself, as shown in the example below:
- configure system security cpm-filter
- config>sys>security>cpm-filter# default-action accept
- config>sys>security>cpm-filter# ip-filter
- config>sys>sec>cpm>ip-filter# entry 10 create
- cfg>sys>sec>cpm>ip-filter>entry# match protocol "icmp"
- cfg>sys>sec>cpm>ip-filter>entry>match# fragment true
- cfg>sys>sec>cpm>ip-filter>entry>match# exit
- cfg>sys>sec>cpm>ip-filter>entry# action drop
- cfg>sys>sec>cpm>ip-filter>entry# exit
- config>sys>sec>cpm>ip-filter# no shutdown
- config>sys>sec>cpm>ip-filter# exit
- config>sys>security>cpm-filter# exit all