CVE-2021-34737

CVE	CVE-2021-34737
State	PUBLIC
Assigner	[email protected]
Source Priority	CVE Program / NVD first with legacy fallback
Published	2021-09-09 05:15:00 UTC
Updated	2023-11-07 03:36:00 UTC
Description	A vulnerability in the DHCP version 4 (DHCPv4) server feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to trigger a crash of the dhcpd process, resulting in a denial of service (DoS) condition. This vulnerability exists because certain DHCPv4 messages are improperly validated when they are processed by an affected device. An attacker could exploit this vulnerability by sending a malformed DHCPv4 message to an affected device. A successful exploit could allow the attacker to cause a NULL pointer dereference, resulting in a crash of the dhcpd process. While the dhcpd process is restarting, which may take up to approximately two minutes, DHCPv4 server services are unavailable on the affected device. This could temporarily prevent network access to clients that join the network during that time period. Note: Only the dhcpd process crashes and eventually restarts automatically. The router does not reload.

Problem Types: CWE-476

Type	Vendor	Product	Version	Update	Edition	Language
Hardware	Cisco	Asr 9000v-v2	-	All	All	All
Hardware	Cisco	Asr 9001	-	All	All	All
Hardware	Cisco	Asr 9006	-	All	All	All
Hardware	Cisco	Asr 9010	-	All	All	All
Hardware	Cisco	Asr 9901	-	All	All	All
Hardware	Cisco	Asr 9902	-	All	All	All
Hardware	Cisco	Asr 9903	-	All	All	All
Hardware	Cisco	Asr 9904	-	All	All	All
Hardware	Cisco	Asr 9906	-	All	All	All
Hardware	Cisco	Asr 9910	-	All	All	All
Hardware	Cisco	Asr 9912	-	All	All	All
Hardware	Cisco	Asr 9922	-	All	All	All
Operating System	Cisco	Ios Xr	All	All	All	All
Operating System	Cisco	Ios Xr	All	All	All	All
Hardware	Cisco	Ios Xrv 9000	-	All	All	All
Hardware	Cisco	Ncs540-12z20g-sys-a	-	All	All	All
Hardware	Cisco	Ncs540-12z20g-sys-d	-	All	All	All
Hardware	Cisco	Ncs540-24z8q2c-m	-	All	All	All
Hardware	Cisco	Ncs540-24z8q2c-sys	-	All	All	All
Hardware	Cisco	Ncs540-28z4c-sys-a	-	All	All	All
Hardware	Cisco	Ncs540-28z4c-sys-d	-	All	All	All
Hardware	Cisco	Ncs540-acc-sys	-	All	All	All
Hardware	Cisco	Ncs540x-12z16g-sys-a	-	All	All	All
Hardware	Cisco	Ncs540x-12z16g-sys-d	-	All	All	All
Hardware	Cisco	Ncs540x-16z4g8q2c-a	-	All	All	All
Hardware	Cisco	Ncs540x-16z4g8q2c-d	-	All	All	All
Hardware	Cisco	Ncs540x-acc-sys	-	All	All	All
Hardware	Cisco	Ncs 5001	-	All	All	All
Hardware	Cisco	Ncs 5002	-	All	All	All
Hardware	Cisco	Ncs 5011	-	All	All	All
Hardware	Cisco	Ncs 5501	-	All	All	All
Hardware	Cisco	Ncs 5501-se	-	All	All	All
Hardware	Cisco	Ncs 5502	-	All	All	All
Hardware	Cisco	Ncs 5502-se	-	All	All	All
Hardware	Cisco	Ncs 5508	-	All	All	All
Hardware	Cisco	Ncs 5516	-	All	All	All
Hardware	Cisco	Ncs 560-4	-	All	All	All
Hardware	Cisco	Ncs 560-7	-	All	All	All

Reference	Source	Link	Tags
Cisco IOS XR Software DHCP Version 4 Server Denial of Service Vulnerability	CISCO	tools.cisco.com
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

No vendor comments have been submitted for this CVE.

317042 Cisco Internetwork Operating System (IOS) XR Software Dynamic Host Configuration Protocol (DHCP) Version 4 Server Denial of Service (DoS) Vulnerability (cisco-sa-iosxr-dhcp-dos-pjPVReLU)