Cisco IOS XE vulnerabilities

CVE-2020-3407 [HIGH] CWE-476 CVE-2020-3407: A vulnerability in the RESTCONF and NETCONF-YANG access control list (ACL) function of Cisco IOS XE A vulnerability in the RESTCONF and NETCONF-YANG access control list (ACL) function of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload. The vulnerability is due to incorrect processing of the ACL that is tied to the RESTCONF or NETCONF-YANG feature. An attacker could exploit this vulnerability by access

CVE-2020-3359 [HIGH] CWE-20 CVE-2020-3359: A vulnerability in the multicast DNS (mDNS) feature of Cisco IOS XE Software for Cisco Catalyst 9800 A vulnerability in the multicast DNS (mDNS) feature of Cisco IOS XE Software for Cisco Catalyst 9800 Series Wireless Controllers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to improper validation of mDNS packets. An attacker could exploit this vulnerability by sending a crafted mD

CVE-2020-3221 [HIGH] CWE-20 CVE-2020-3221: A vulnerability in the Flexible NetFlow Version 9 packet processor of Cisco IOS XE Software for Cisc A vulnerability in the Flexible NetFlow Version 9 packet processor of Cisco IOS XE Software for Cisco Catalyst 9800 Series Wireless Controllers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper validation of parameters in a Flexible NetFlow Version 9 re

CVE-2019-16009 [HIGH] CWE-352 CVE-2019-16009: A vulnerability in the web UI of Cisco IOS and Cisco IOS XE Software could allow an unauthenticated, A vulnerability in the web UI of Cisco IOS and Cisco IOS XE Software could allow an unauthenticated, remote attacker to conduct a cross-site request forgery (CSRF) attack on an affected system. The vulnerability is due to insufficient CSRF protections for the web UI on an affected device. An attacker could exploit this vulnerability by persuading a us

CVE-2019-1904 [HIGH] CWE-352 CVE-2019-1904: A vulnerability in the web-based UI (web UI) of Cisco IOS XE Software could allow an unauthenticated A vulnerability in the web-based UI (web UI) of Cisco IOS XE Software could allow an unauthenticated, remote attacker to conduct a cross-site request forgery (CSRF) attack on an affected system. The vulnerability is due to insufficient CSRF protections for the web UI on an affected device. An attacker could exploit this vulnerability by persuading a use

CVE-2020-3510 [HIGH] CWE-388 CVE-2020-3510: A vulnerability in the Umbrella Connector component of Cisco IOS XE Software for Cisco Catalyst 9200 A vulnerability in the Umbrella Connector component of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches could allow an unauthenticated, remote attacker to trigger a reload, resulting in a denial of service condition on an affected device. The vulnerability is due to insufficient error handling when parsing DNS requests. An attacker could ex

CVE-2021-1624 [HIGH] CWE-399 CVE-2021-1624: A vulnerability in the Rate Limiting Network Address Translation (NAT) feature of Cisco IOS XE Softw A vulnerability in the Rate Limiting Network Address Translation (NAT) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause high CPU utilization in the Cisco QuantumFlow Processor of an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to mishandling of the rate limiting fea

CVE-2021-1565 [HIGH] CWE-415 CVE-2021-1565: Multiple vulnerabilities in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol Multiple vulnerabilities in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE Software for Cisco Catalyst 9000 Family Wireless Controllers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. These vulnerabilities are due to insufficient vali

CVE-2023-20072 [HIGH] CWE-20 CVE-2023-20072: A vulnerability in the fragmentation handling code of tunnel protocol packets in Cisco IOS XE Softwa A vulnerability in the fragmentation handling code of tunnel protocol packets in Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected system to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to the improper handling of large fragmented tunnel protocol packets. One example of a t

CVE-2026-20270 [HIGH] CWE-682 CVE-2026-20270: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE So As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20270 are related t

CVE-2026-20273 [HIGH] CWE-20 CVE-2026-20273: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE So As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20273 are related

CVE-2021-1223 [HIGH] CWE-693 CVE-2021-1223: Multiple Cisco products are affected by a vulnerability in the Snort detection engine that could all Multiple Cisco products are affected by a vulnerability in the Snort detection engine that could allow an unauthenticated, remote attacker to bypass a configured file policy for HTTP. The vulnerability is due to incorrect handling of an HTTP range header. An attacker could exploit this vulnerability by sending crafted HTTP packets through an affected de

CVE-2019-12664 [HIGH] CWE-200 CVE-2019-12664: A vulnerability in the Dialer interface feature for ISDN connections in Cisco IOS XE Software for Ci A vulnerability in the Dialer interface feature for ISDN connections in Cisco IOS XE Software for Cisco 4000 Series Integrated Services Routers (ISRs) could allow an unauthenticated, adjacent attacker to pass IPv4 traffic through an ISDN channel prior to successful PPP authentication. The vulnerability is due to insufficient validation of the state of

CVE-2026-20124 [HIGH] CWE-772 CVE-2026-20124: A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS XE Software A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS XE Software could allow an authenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to improper error handling when parsing SNMP requests. This vulnerability affects all versio

CVE-2022-20693 [HIGH] CWE-74 CVE-2022-20693: A vulnerability in the web UI feature of Cisco IOS XE Software could allow an authenticated, remote A vulnerability in the web UI feature of Cisco IOS XE Software could allow an authenticated, remote attacker to perform an injection attack against an affected device. This vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending crafted input to the web UI API. A successful exploit could allow the a

CVE-2019-1737 [HIGH] CWE-400 CVE-2019-1737: A vulnerability in the processing of IP Service Level Agreement (SLA) packets by Cisco IOS Software A vulnerability in the processing of IP Service Level Agreement (SLA) packets by Cisco IOS Software and Cisco IOS XE software could allow an unauthenticated, remote attacker to cause an interface wedge and an eventual denial of service (DoS) condition on the affected device. The vulnerability is due to improper socket resources handling in the IP SLA res

CVE-2019-1747 [HIGH] CWE-20 CVE-2019-1747: A vulnerability in the implementation of the Short Message Service (SMS) handling functionality of C A vulnerability in the implementation of the Short Message Service (SMS) handling functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition on an affected device. The vulnerability is due to improper processing of SMS protocol data units (PDUs) that are enc

CVE-2020-3492 [HIGH] CWE-20 CVE-2020-3492: A vulnerability in the Flexible NetFlow Version 9 packet processor of Cisco IOS XE Software for Cisc A vulnerability in the Flexible NetFlow Version 9 packet processor of Cisco IOS XE Software for Cisco Catalyst 9800 Series Wireless Controllers and Cisco AireOS Software for Cisco Wireless LAN Controllers (WLC) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to i

CVE-2020-3399 [HIGH] CWE-126 CVE-2020-3399: A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processi A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE Software for Cisco Catalyst 9800 Series Wireless Controllers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition of an affected device. The vulnerability is due to insufficient input validation d

CVE-2021-34697 [HIGH] CWE-665 CVE-2021-34697: A vulnerability in the Protection Against Distributed Denial of Service Attacks feature of Cisco IOS A vulnerability in the Protection Against Distributed Denial of Service Attacks feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to conduct denial of service (DoS) attacks to or through the affected device. This vulnerability is due to incorrect programming of the half-opened connections limit, TCP SYN flood limit, or T