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.
This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 5.8, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts and limited availability for affected systems. Impacting 37 products from cisco, from cisco, from cisco and 34 others, organizations running these solutions should prioritize assessment and patching.
Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2021-09-09T05:15:11.963
2024-11-21T06:11:05.107
Modified
CVSSv3.1: 5.8 (MEDIUM)
AV:N/AC:L/Au:N/C:N/I:N/A:P
10.0
2.9
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Operating System | cisco | ios_xr | < 7.3.2 | Yes |
| Operating System | cisco | ios_xr | ≤ 7.4.1 | Yes |
| Hardware | cisco | asr_9000v-v2 | - | No |
| Hardware | cisco | asr_9001 | - | No |
| Hardware | cisco | asr_9006 | - | No |
| Hardware | cisco | asr_9010 | - | No |
| Hardware | cisco | asr_9901 | - | No |
| Hardware | cisco | asr_9902 | - | No |
| Hardware | cisco | asr_9903 | - | No |
| Hardware | cisco | asr_9904 | - | No |
| Hardware | cisco | asr_9906 | - | No |
| Hardware | cisco | asr_9910 | - | No |
| Hardware | cisco | asr_9912 | - | No |
| Hardware | cisco | asr_9922 | - | No |
| Operating System | cisco | ios_xr | < 7.3.2 | Yes |
| Operating System | cisco | ios_xr | ≤ 7.4.1 | Yes |
| Hardware | cisco | ios_xrv_9000 | - | No |
| Operating System | cisco | ios_xr | < 7.3.2 | Yes |
| Operating System | cisco | ios_xr | < 7.4.1 | Yes |
| Hardware | cisco | ncs540-12z20g-sys-a | - | No |
| Hardware | cisco | ncs540-12z20g-sys-d | - | No |
| Hardware | cisco | ncs540-24z8q2c-m | - | No |
| Hardware | cisco | ncs540-24z8q2c-sys | - | No |
| Hardware | cisco | ncs540-28z4c-sys-a | - | No |
| Hardware | cisco | ncs540-28z4c-sys-d | - | No |
| Hardware | cisco | ncs540-acc-sys | - | No |
| Hardware | cisco | ncs540x-12z16g-sys-a | - | No |
| Hardware | cisco | ncs540x-12z16g-sys-d | - | No |
| Hardware | cisco | ncs540x-16z4g8q2c-a | - | No |
| Hardware | cisco | ncs540x-16z4g8q2c-d | - | No |
| Hardware | cisco | ncs540x-acc-sys | - | No |
| Operating System | cisco | ios_xr | < 7.3.2 | Yes |
| Operating System | cisco | ios_xr | < 7.4.1 | Yes |
| Hardware | cisco | ncs_5001 | - | No |
| Hardware | cisco | ncs_5002 | - | No |
| Hardware | cisco | ncs_5011 | - | No |
| Operating System | cisco | ios_xr | < 7.3.2 | Yes |
| Operating System | cisco | ios_xr | < 7.4.1 | Yes |
| Hardware | cisco | ncs_560-4 | - | No |
| Hardware | cisco | ncs_560-7 | - | No |
| Operating System | cisco | ios_xr | < 7.3.2 | Yes |
| Operating System | cisco | ios_xr | < 7.4.1 | Yes |
| Hardware | cisco | ncs_5501 | - | No |
| Hardware | cisco | ncs_5501-se | - | No |
| Hardware | cisco | ncs_5502 | - | No |
| Hardware | cisco | ncs_5502-se | - | No |
| Hardware | cisco | ncs_5508 | - | No |
| Hardware | cisco | ncs_5516 | - | No |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For cisco's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.