Cisco IOS and Cisco IOS XE Software UDP Packet Processing Denial of Service Vulnerability
Cisco Security Advisory
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cisco-sa-20170906-ios-udp
Final
1.2
1.0
2017-09-06T16:35:50
Initial public release.
1.1
2017-09-07T13:35:32
Corrected the list of Cisco bug IDs.
1.2
2022-12-17T05:53:01
Updated exploitation information.
2017-09-06T16:00:00
2022-12-17T05:53:01
TVCE
A vulnerability in the UDP processing code of Cisco IOS and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the input queue of an affected system to hold UDP packets, causing an interface queue wedge and a denial of service (DoS) condition.
The vulnerability is due to Cisco IOS Software application changes that create UDP sockets and leave the sockets idle without closing them. An attacker could exploit this vulnerability by sending UDP packets with a destination port of 0 to an affected device. A successful exploit could allow the attacker to cause UDP packets to be held in the input interfaces queue, resulting in a DoS condition. The input interface queue will stop holding UDP packets when it receives 250 packets.
There are workarounds that address this vulnerability.
This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-ios-udp ["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-ios-udp"]
This vulnerability affects Cisco IOS and Cisco IOS XE Software. For information about affected software releases, consult the Cisco bug ID(s) at the top of this advisory.
No other Cisco products are currently known to be affected by this vulnerability.
To work around this vulnerability, administrators can set a maximum hold queue value that is greater than 250 for all device interfaces. The following example shows how to set the value to 350 by using the hold queue in interface configuration command:
Router# configure terminal
Router(config)# interface gigabitEthernet 1 Router(config-if)# hold-queue 350 in
Administrators can also configure an access-control list (ACL) that blocks UDP packets with a destination port of 0 and apply the ACL to all device interfaces, for example:
Extended IP access list 180
10 deny udp any any eq 0
For information about fixed software releases, consult the Cisco bug ID(s) at the top of this advisory.
When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories and Alerts page ["https://www.cisco.com/go/psirt"], to determine exposure and a complete upgrade solution.
In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.
To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy ["https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html"]. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
In March 2022, the Cisco Product Security Incident Response Team (PSIRT) became aware of additional attempted exploitation of this vulnerability in the wild. Cisco continues to strongly recommend that customers upgrade to a fixed software release to remediate this vulnerability.
THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.
A standalone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy and may lack important information or contain factual errors. The information in this document is intended for end users of Cisco products.
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-ios-udp
Cisco IOS and Cisco IOS XE Software UDP Packet Processing Denial of Service Vulnerability
Cisco IOS
Cisco IOS XE Software 3.14.0S
Cisco IOS XE Software 3.14.1S
Cisco IOS XE Software 3.14.2S
Cisco IOS XE Software 3.14.3S
Cisco IOS XE Software 3.14.4S
Cisco IOS XE Software 3.15.0S
Cisco IOS XE Software 3.15.1S
Cisco IOS XE Software 3.15.2S
Cisco IOS XE Software 3.15.1cS
Cisco IOS XE Software 3.15.3S
Cisco IOS XE Software 3.15.4S
Cisco IOS XE Software 3.16.0S
Cisco IOS XE Software 3.16.1S
Cisco IOS XE Software 3.16.0aS
Cisco IOS XE Software 3.16.1aS
Cisco IOS XE Software 3.16.2S
Cisco IOS XE Software 3.16.2aS
Cisco IOS XE Software 3.16.0bS
Cisco IOS XE Software 3.16.0cS
Cisco IOS XE Software 3.16.3S
Cisco IOS XE Software 3.16.2bS
Cisco IOS XE Software 3.16.3aS
Cisco IOS XE Software 3.16.4S
Cisco IOS XE Software 3.16.4aS
Cisco IOS XE Software 3.16.4bS
Cisco IOS XE Software 3.16.4gS
Cisco IOS XE Software 3.16.5S
Cisco IOS XE Software 3.16.4cS
Cisco IOS XE Software 3.16.4dS
Cisco IOS XE Software 3.16.4eS
Cisco IOS XE Software 3.16.6S
Cisco IOS XE Software 3.16.5aS
Cisco IOS XE Software 3.16.5bS
Cisco IOS XE Software 3.17.0S
Cisco IOS XE Software 3.17.1S
Cisco IOS XE Software 3.17.2S
Cisco IOS XE Software 3.17.1aS
Cisco IOS XE Software 3.17.3S
Cisco IOS XE Software 3.18.0aS
Cisco IOS XE Software 3.18.0S
Cisco IOS XE Software 3.18.1S
Cisco IOS XE Software 3.18.2S
Cisco IOS XE Software 3.18.3S
Cisco IOS and IOS XE Software UDP Denial of Service Vulnerability
CSCup10024
CSCup10024,CSCva95506,CSCve64219,CSCvc96281
Complete.
CVE-2017-6627
CVRFPID-2097
CVRFPID-206178
CVRFPID-206180
CVRFPID-206181
CVRFPID-206191
CVRFPID-206192
CVRFPID-206193
CVRFPID-210079
CVRFPID-210081
CVRFPID-212268
CVRFPID-212408
CVRFPID-212411
CVRFPID-212412
CVRFPID-213476
CVRFPID-213477
CVRFPID-213478
CVRFPID-213635
CVRFPID-213700
CVRFPID-213776
CVRFPID-213777
CVRFPID-213778
CVRFPID-213779
CVRFPID-217234
CVRFPID-217264
CVRFPID-217265
CVRFPID-217266
CVRFPID-217267
CVRFPID-217268
CVRFPID-217270
CVRFPID-217271
CVRFPID-217272
CVRFPID-217273
CVRFPID-220993
CVRFPID-222257
CVRFPID-222693
CVRFPID-222694
CVRFPID-222925
CVRFPID-222942
CVRFPID-223252
CVRFPID-224702
CVRFPID-225099
CVRFPID-225466
CVRFPID-225832
CVRFPID-226078
5.3
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
To work around this vulnerability, administrators can set a maximum hold queue value that is greater than 250 for all device interfaces. The following example shows how to set the value to 350 by using the hold queue in interface configuration command:
Router# configure terminal
Router(config)# interface gigabitEthernet 1 Router(config-if)# hold-queue 350 in
Administrators can also configure an access-control list (ACL) that blocks UDP packets with a destination port of 0 and apply the ACL to all device interfaces, for example:
Extended IP access list 180
10 deny udp any any eq 0
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-ios-udp
Cisco IOS and Cisco IOS XE Software UDP Packet Processing Denial of Service Vulnerability