CVE-2021-34737

🗓️ 09 Sep 2021 05:01:30Reported by ciscoType

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

Reporter	Title	Published	Views	Family All 11
Circl	CVE-2021-34737	9 Sep 202112:29	–	circl
Cisco	Cisco IOS XR Software DHCP Version 4 Server Denial of Service Vulnerability	8 Sep 202116:00	–	cisco
Tenable Nessus	Cisco IOS XR Software DHCP Version 4 Server DoS (cisco-sa-iosxr-dhcp-dos-pjPVReLU)	10 Sep 202100:00	–	nessus
CNNVD	Cisco IOS XR 代码问题漏洞	8 Sep 202100:00	–	cnnvd
CNVD	Cisco IOS XR Software DHCP Denial of Service Vulnerability	9 Sep 202100:00	–	cnvd
Cvelist	CVE-2021-34737 Cisco IOS XR Software DHCP Version 4 Server Denial of Service Vulnerability	9 Sep 202105:01	–	cvelist
EUVD	EUVD-2021-21387	7 Oct 202500:30	–	euvd
NCSC	Vulnerabilities fixed in Cisco IOS XR	10 Sep 202100:00	–	ncsc
NVD	CVE-2021-34737	9 Sep 202105:15	–	nvd
Prion	Null pointer dereference	9 Sep 202105:15	–	prion

NVD

Node

cisco ios_xrRange<7.3.2

cisco ios_xrRange7.4.0–7.4.1

AND

cisco asr_9000v-v2Match-

cisco asr_9001Match-

cisco asr_9006Match-

cisco asr_9010Match-

cisco asr_9901Match-

cisco asr_9902Match-

cisco asr_9903Match-

cisco asr_9904Match-

cisco asr_9906Match-

cisco asr_9910Match-

cisco asr_9912Match-

cisco asr_9922Match-

Node

cisco ios_xrRange<7.3.2

cisco ios_xrRange7.4.0–7.4.1

AND

cisco ios_xrv_9000Match-

Node

cisco ios_xrRange<7.3.2

cisco ios_xrRange7.4.0–7.4.1

AND

cisco ncs540-12z20g-sys-aMatch-

cisco ncs540-12z20g-sys-dMatch-

cisco ncs540-24z8q2c-mMatch-

cisco ncs540-24z8q2c-sysMatch-

cisco ncs540-28z4c-sys-aMatch-

cisco ncs540-28z4c-sys-dMatch-

cisco ncs540-acc-sysMatch-

cisco ncs540x-12z16g-sys-aMatch-

cisco ncs540x-12z16g-sys-dMatch-

cisco ncs540x-16z4g8q2c-aMatch-

cisco ncs540x-16z4g8q2c-dMatch-

cisco ncs540x-acc-sysMatch-

Node

cisco ios_xrRange<7.3.2

cisco ios_xrRange7.4.0–7.4.1

AND

cisco ncs_5001Match-

cisco ncs_5002Match-

cisco ncs_5011Match-

Node

cisco ios_xrRange<7.3.2

cisco ios_xrRange7.4.0–7.4.1

AND

cisco ncs_560-4Match-

cisco ncs_560-7Match-

Node

cisco ios_xrRange<7.3.2

cisco ios_xrRange7.4.0–7.4.1

AND

cisco ncs_5501Match-

cisco ncs_5501-seMatch-

cisco ncs_5502Match-

cisco ncs_5502-seMatch-

cisco ncs_5508Match-

cisco ncs_5516Match-

[
  {
    "product": "Cisco IOS XR Software",
    "vendor": "Cisco",
    "versions": [
      {
        "status": "affected",
        "version": "n/a"
      }
    ]
  }
]

Source	Link
tools	www.tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dhcp-dos-pjPVReLU

21 Nov 2024 06:11Current

6.5Medium risk

Vulners AI Score6.5

CVSS 25

CVSS 3.15.8 - 7.5

EPSS0.00419

SSVC

CWE-476