CVSS: 4.7EPSS: 0%CPEs: 312EXPL: 1CVE-2021-27853 – L2 network filtering can be bypassed using stacked VLAN0 and LLC/SNAP headers
https://notcve.org/view.php?id=CVE-2021-27853
Layer 2 network filtering capabilities such as IPv6 RA guard or ARP inspection can be bypassed using combinations of VLAN 0 headers and LLC/SNAP headers. Las capacidades de filtrado de la red de capa 2, como la protección IPv6 RA o la inspección ARP, pueden omitirse usando combinaciones de encabezados VLAN 0 y encabezados LLC/SNAP • https://blog.champtar.fr/VLAN0_LLC_SNAP https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08 https://kb.cert.org/vuls/id/855201 https://standards.ieee.org/ieee/802.1Q/10323 https://standards.ieee.org/ieee/802.2/1048 https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-VU855201-J3z8CKTX • CWE-290: Authentication Bypass by Spoofing •
CVSS: 7.7EPSS: 0%CPEs: 965EXPL: 0CVE-2021-1620 – Cisco IOS and IOS XE Software IKEv2 AutoReconnect Feature Denial of Service Vulnerability
https://notcve.org/view.php?id=CVE-2021-1620
A vulnerability in the Internet Key Exchange Version 2 (IKEv2) support for the AutoReconnect feature of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to exhaust the free IP addresses from the assigned local pool. This vulnerability occurs because the code does not release the allocated IP address under certain failure conditions. An attacker could exploit this vulnerability by trying to connect to the device with a non-AnyConnect client. A successful exploit could allow the attacker to exhaust the IP addresses from the assigned local pool, which prevents users from logging in and leads to a denial of service (DoS) condition. Una vulnerabilidad en el soporte de Intercambio de Claves de Internet Versión 2 (IKEv2) para la funcionalidad AutoReconnect de Cisco IOS Software y Cisco IOS XE Software podría permitir a un atacante remoto autenticado agotar las direcciones IP libres del pool local asignado. • https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ikev2-ebFrwMPr • CWE-563: Assignment to Variable without Use CWE-772: Missing Release of Resource after Effective Lifetime •
CVSS: 6.8EPSS: 0%CPEs: 203EXPL: 0CVE-2021-34703 – Cisco IOS and IOS XE Software Link Layer Discovery Protocol Denial of Service Vulnerability
https://notcve.org/view.php?id=CVE-2021-34703
A vulnerability in the Link Layer Discovery Protocol (LLDP) message parser of Cisco IOS Software and Cisco IOS XE Software could allow an attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to improper initialization of a buffer. An attacker could exploit this vulnerability via any of the following methods: An authenticated, remote attacker could access the LLDP neighbor table via either the CLI or SNMP while the device is in a specific state. An unauthenticated, adjacent attacker could corrupt the LLDP neighbor table by injecting specific LLDP frames into the network and then waiting for an administrator of the device or a network management system (NMS) managing the device to retrieve the LLDP neighbor table of the device via either the CLI or SNMP. An authenticated, adjacent attacker with SNMP read-only credentials or low privileges on the device CLI could corrupt the LLDP neighbor table by injecting specific LLDP frames into the network and then accessing the LLDP neighbor table via either the CLI or SNMP. • https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-lldp-dos-sBnuHSjT • CWE-456: Missing Initialization of a Variable CWE-665: Improper Initialization •
CVSS: 7.4EPSS: 0%CPEs: 149EXPL: 0CVE-2020-3508 – Cisco IOS XE Software for Cisco ASR 1000 Series 20-Gbps Embedded Services Processor IP ARP Denial of Service Vulnerability
https://notcve.org/view.php?id=CVE-2020-3508
A vulnerability in the IP Address Resolution Protocol (ARP) feature of Cisco IOS XE Software for Cisco ASR 1000 Series Aggregation Services Routers with a 20-Gbps Embedded Services Processor (ESP) installed could allow an unauthenticated, adjacent attacker to cause an affected device to reload, resulting in a denial of service condition. The vulnerability is due to insufficient error handling when an affected device has reached platform limitations. An attacker could exploit this vulnerability by sending a malicious series of IP ARP messages to an affected device. A successful exploit could allow the attacker to exhaust system resources, which would eventually cause the affected device to reload. Una vulnerabilidad en la funcionalidad de Address Resolution Protocol (ARP) de IP de Cisco IOS XE Software para Cisco ASR 1000 Series Aggregation Services Routers con un Embedded Services Processor (ESP) de 20-Gbps instalado, podría permitir a un atacante adyacente no autenticado causar la recarga de un dispositivo afectado, resultando en una condición de denegación de servicio. • https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esp20-arp-dos-GvHVggqJ • CWE-400: Uncontrolled Resource Consumption •
CVSS: 7.4EPSS: 0%CPEs: 132EXPL: 0CVE-2020-3512 – Cisco IOS and IOS XE Software PROFINET Link Layer Discovery Protocol Denial of Service Vulnerability
https://notcve.org/view.php?id=CVE-2020-3512
A vulnerability in the PROFINET handler for Link Layer Discovery Protocol (LLDP) messages of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a crash on an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient validation of LLDP messages in the PROFINET LLDP message handler. An attacker could exploit this vulnerability by sending a malicious LLDP message to an affected device. A successful exploit could allow the attacker to cause the affected device to reload. Una vulnerabilidad en el manejador PROFINET para los mensajes Link Layer Discovery Protocol (LLDP) de Cisco IOS Software y Cisco IOS XE Software, podría permitir a un atacante adyacente no autenticado causar un bloqueo en un dispositivo afectado, resultando en una condición de denegación de servicio (DoS). • https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-profinet-dos-65qYG3W5 • CWE-388: 7PK - Errors CWE-400: Uncontrolled Resource Consumption •