CVE-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 •
CVE-2022-20824 – Cisco FXOS and NX-OS Software Cisco Discovery Protocol Denial of Service and Arbitrary Code Execution Vulnerability
https://notcve.org/view.php?id=CVE-2022-20824
A vulnerability in the Cisco Discovery Protocol feature of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to execute arbitrary code with root privileges or cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper input validation of specific values that are within a Cisco Discovery Protocol message. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected device. A successful exploit could allow the attacker to execute arbitrary code with root privileges or cause the Cisco Discovery Protocol process to crash and restart multiple times, which would cause the affected device to reload, resulting in a DoS condition. Note: Cisco Discovery Protocol is a Layer 2 protocol. • https://security.netapp.com/advisory/ntap-20220923-0001 https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-cdp-dos-ce-wWvPucC9 • CWE-121: Stack-based Buffer Overflow CWE-787: Out-of-bounds Write •
CVE-2022-20823 – Cisco NX-OS Software OSPFv3 Denial of Service Vulnerability
https://notcve.org/view.php?id=CVE-2022-20823
A vulnerability in the OSPF version 3 (OSPFv3) feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to incomplete input validation of specific OSPFv3 packets. An attacker could exploit this vulnerability by sending a malicious OSPFv3 link-state advertisement (LSA) to an affected device. A successful exploit could allow the attacker to cause the OSPFv3 process to crash and restart multiple times, causing the affected device to reload and resulting in a DoS condition. Note: The OSPFv3 feature is disabled by default. • https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-ospfv3-dos-48qutcu • CWE-125: Out-of-bounds Read CWE-126: Buffer Over-read •
CVE-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 •
CVE-2021-34714 – Multiple Cisco Operating Systems Unidirectional Link Detection Denial of Service Vulnerability
https://notcve.org/view.php?id=CVE-2021-34714
A vulnerability in the Unidirectional Link Detection (UDLD) feature of Cisco FXOS Software, Cisco IOS Software, Cisco IOS XE Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause an affected device to reload. This vulnerability is due to improper input validation of the UDLD packets. An attacker could exploit this vulnerability by sending specifically crafted UDLD packets to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. Note: The UDLD feature is disabled by default, and the conditions to exploit this vulnerability are strict. • https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-nxos-xr-udld-dos-W5hGHgtQ • CWE-20: Improper Input Validation •