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: 7.2EPSS: 0%CPEs: 87EXPL: 0CVE-2019-12649 – Cisco IOS XE Software Digital Signature Verification Bypass Vulnerability
https://notcve.org/view.php?id=CVE-2019-12649
A vulnerability in the Image Verification feature of Cisco IOS XE Software could allow an authenticated, local attacker to install and boot a malicious software image or execute unsigned binaries on an affected device. The vulnerability exists because, under certain circumstances, an affected device can be configured to not verify the digital signatures of system image files during the boot process. An attacker could exploit this vulnerability by abusing a specific feature that is part of the device boot process. A successful exploit could allow the attacker to install and boot a malicious software image or execute unsigned binaries on the targeted device. Una vulnerabilidad en la funcionalidad de Comprobación de Imagen del Software Cisco IOS XE, podría permitir a un atacante local autenticado instalar y arrancar una imagen de software malicioso o ejecutar archivos binarios sin firmar en un dispositivo afectado. • https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190925-iosxe-digsig-bypass • CWE-347: Improper Verification of Cryptographic Signature •
CVSS: 7.4EPSS: 0%CPEs: 48EXPL: 0CVE-2018-0165
https://notcve.org/view.php?id=CVE-2018-0165
A vulnerability in the Internet Group Management Protocol (IGMP) packet-processing functionality of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to exhaust buffers on an affected device, resulting in a denial of service (DoS) condition, aka a Memory Leak. The vulnerability is due to the affected software insufficiently processing IGMP Membership Query packets that are sent to an affected device. An attacker could exploit this vulnerability by sending a large number of IGMP Membership Query packets, which contain certain values, to an affected device. A successful exploit could allow the attacker to exhaust buffers on the affected device, resulting in a DoS condition that requires the device to be reloaded manually. This vulnerability affects: Cisco Catalyst 4500 Switches with Supervisor Engine 8-E, if they are running Cisco IOS XE Software Release 3.x.x.E and IP multicast routing is configured; Cisco devices that are running Cisco IOS XE Software Release 16.x, if IP multicast routing is configured. • http://www.securityfocus.com/bid/103568 http://www.securitytracker.com/id/1040592 https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-igmp • CWE-399: Resource Management Errors CWE-772: Missing Release of Resource after Effective Lifetime •