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 crash of the dhcpd process. While the dhcpd process is restarting, which may take 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 and rely on the DHCPv4 server of the affected device.
Notes:
Only the dhcpd process crashes and eventually restarts automatically. The router does not reload.
This vulnerability only applies to DHCPv4. DHCP version 6 (DHCPv6) is not affected.
problem types: NULL Pointer Dereference
affected:
{
vendor: Cisco
product: Cisco IOS XR Software
versions:
version: 5.2.0, status: affected
version: 5.2.1, status: affected
version: 5.2.2, status: affected
version: 5.2.4, status: affected
version: 5.2.3, status: affected
version: 5.2.5, status: affected
version: 5.2.47, status: affected
version: 5.3.0, status: affected
version: 5.3.1, status: affected
version: 5.3.2, status: affected
version: 5.3.3, status: affected
version: 5.3.4, status: affected
version: 6.0.0, status: affected
version: 6.0.1, status: affected
version: 6.0.2, status: affected
version: 6.1.1, status: affected
version: 6.1.2, status: affected
version: 6.1.3, status: affected
version: 6.1.4, status: affected
version: 6.1.12, status: affected
version: 6.1.22, status: affected
version: 6.1.32, status: affected
version: 6.1.36, status: affected
version: 6.1.42, status: affected
version: 6.2.1, status: affected
version: 6.2.2, status: affected
version: 6.2.3, status: affected
version: 6.2.25, status: affected
version: 6.2.11, status: affected
version: 6.3.2, status: affected
version: 6.3.3, status: affected
version: 6.3.15, status: affected
version: 6.4.1, status: affected
version: 6.4.2, status: affected
version: 6.4.3, status: affected
version: 6.5.1, status: affected
version: 6.5.2, status: affected
version: 6.5.3, status: affected
version: 6.5.25, status: affected
version: 6.5.26, status: affected
version: 6.5.28, status: affected
version: 6.5.29, status: affected
version: 6.5.32, status: affected
version: 6.5.33, status: affected
version: 6.6.2, status: affected
version: 6.6.3, status: affected
version: 6.6.25, status: affected
version: 6.6.4, status: affected
version: 7.0.1, status: affected
version: 7.0.2, status: affected
version: 7.0.12, status: affected
version: 7.0.14, status: affected
version: 7.1.1, status: affected
version: 7.1.15, status: affected
version: 7.1.2, status: affected
version: 7.1.3, status: affected
version: 6.7.1, status: affected
version: 6.7.2, status: affected
version: 6.7.3, status: affected
version: 6.7.4, status: affected
version: 7.2.0, status: affected
version: 7.2.1, status: affected
version: 7.2.2, status: affected
version: 7.3.1, status: affected
version: 7.3.15, status: affected
version: 7.3.2, status: affected
version: 7.3.3, status: affected
version: 7.3.5, status: affected
version: 7.4.1, status: affected
version: 7.4.2, status: affected
version: 6.8.1, status: affected
version: 6.8.2, status: affected
version: 7.5.1, status: affected
version: 7.5.3, status: affected
version: 7.5.2, status: affected
version: 7.5.4, status: affected
version: 7.5.5, status: affected
version: 7.6.1, status: affected
version: 7.6.2, status: affected
version: 7.7.1, status: affected
version: 7.7.2, status: affected
version: 7.7.21, status: affected
version: 6.9.1, status: affected
version: 6.9.2, status: affected
version: 7.8.1, status: affected
version: 7.8.2, status: affected
version: 7.9.1, status: affected
version: 7.9.2, status: affected
version: 7.9.21, status: affected
version: 7.10.1, status: affected
version: 7.10.2, status: affected
}
metrics:
format: cvssV3_1
cvssV3_1: [
version: 3.1
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
baseScore: 5.3
baseSeverity: MEDIUM
attackVector: NETWORK
attackComplexity: LOW
privilegesRequired: NONE
userInteraction: NONE
scope: UNCHANGED
confidentialityImpact: NONE
integrityImpact: NONE
availabilityImpact: LOW
]
exploits: The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.