5
CVSSv2

CVE-2021-34737

Published: 09/09/2021 Updated: 07/11/2023
CVSS v2 Base Score: 5 | Impact Score: 2.9 | Exploitability Score: 10
CVSS v3 Base Score: 7.5 | Impact Score: 3.6 | Exploitability Score: 3.9
VMScore: 445
Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P

Vulnerability Summary

A vulnerability in the DHCP version 4 (DHCPv4) server feature of Cisco IOS XR Software could allow an unauthenticated, remote malicious user 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 malicious user 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.

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Vendor Advisories

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 de ...