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Cisco IOS

Ranked by severity, then by exploit likelihood. Click a CVE ID for its full record.

620CVEs
CVE-2013-1217
The generic input/output control implementation in Cisco IOS does not properly manage buffers, which allows remote authenticated users to cause a denial of service (device reload) by sending many SNMP requests at the same time, aka Bug ID CSCub41105.
Published 2013-04-24 · Modified
6.8EPSS 0.015
CVE-2013-6686
The SSL VPN implementation in Cisco IOS 15.3(1)T2 and earlier allows remote authenticated users to cause a denial of service (interface queue wedge) via crafted DTLS packets in an SSL session, aka Bug IDs CSCuh97409 and CSCud90568.
Published 2013-11-16 · Modified
6.8EPSS 0.015
CVE-2015-0598
The RADIUS implementation in Cisco IOS and IOS XE allows remote attackers to cause a denial of service (device reload) via crafted IPv6 Attributes in Access-Accept packets, aka Bug IDs CSCur84322 and CSCur27693.
Published 2015-03-06 · Modified
6.8EPSS 0.015
CVE-2016-6410
The Cisco Application-hosting Framework (CAF) component in Cisco IOS 15.6(1)T1 and IOS XE, when the IOx feature set is enabled, allows remote authenticated users to read arbitrary files via unspecified vectors, aka Bug ID CSCuy19856.
Published 2016-09-24 · Modified
6.8EPSS 0.014
CVE-2021-34703
Cisco IOS and IOS XE Software Link Layer Discovery Protocol Denial of Service Vulnerability
Published 2021-09-23 · Modified
6.8EPSS 0.012
CVE-2010-3050
Cisco IOS before 12.2(33)SXI allows remote authenticated users to cause a denial of service (device reboot).
Published 2017-09-25 · Modified
6.8EPSS 0.011
CVE-2012-5030
Cisco IOS before 15.2(4)S6 does not initialize an unspecified variable, which might allow remote authenticated users to cause a denial of service (CPU consumption, watchdog timeout, crash) by walking specific SNMP objects.
Published 2017-08-02 · Modified
6.8EPSS 0.011
CVE-2012-5036
Cisco IOS before 12.2(50)SY1 allows remote authenticated users to cause a denial of service (memory consumption) via a sequence of VTY management sessions (aka exec sessions), aka Bug ID CSCtn43662.
Published 2014-04-23 · Modified
6.8EPSS 0.011
CVE-2012-5422
Unspecified vulnerability in Cisco IOS before 15.3(2)T on AS5400 devices allows remote authenticated users to cause a denial of service (spurious errors) via unknown vectors, aka Bug ID CSCub61009.
Published 2014-04-23 · Modified
6.8EPSS 0.011
CVE-2015-0709
Cisco IOS 15.5S and IOS XE allow remote authenticated users to cause a denial of service (device crash) by leveraging knowledge of the RADIUS secret and sending crafted RADIUS packets, aka Bug ID CSCur21348.
Published 2015-04-29 · Modified
6.8EPSS 0.011
CVE-2009-0471
Cross-site request forgery (CSRF) vulnerability in the HTTP server in Cisco IOS 12.4(23) allows remote attackers to execute arbitrary commands, as demonstrated by executing the hostname command with a level/15/configure/-/hostname request.
Published 2009-02-06 · Modified
6.8EPSS 0.007
CVE-2023-20081
Cisco Adaptive Security Appliance Software, Firepower Threat Defense Software, IOS Software, and IOS XE Software IPv6 DHCP (DHCPv6) Client Denial of Service Vulnerability
Published 2023-03-23 · Modified
6.8EPSS 0.007
CVE-2013-5522
Cisco IOS on Catalyst 3750X switches has default Service Module credentials, which makes it easier for local users to gain privileges via a Service Module login, aka Bug ID CSCue92286.
Published 2013-10-25 · Modified
6.8EPSS 0.003
CVE-2025-20181
A vulnerability in Cisco IOS Software for Cisco Catalyst 2960X, 2960XR, 2960CX, and 3560CX Series Switches could allow an authenticated, local attacker with privilege level 15 or an unauthenticated attacker with physical access to the device to execute persistent code at boot time and break the chain of trust. This vulnerability is due to missing signature verification for specific files that may be loaded during the device boot process. An attacker could exploit this vulnerability by placing a crafted file into a specific location on an affected device. A successful exploit could allow the attacker to execute arbitrary code at boot time. Because this allows the attacker to bypass a major security feature of the device, Cisco has raised the Security Impact Rating (SIR) of this advisory from Medium to High.
Published 2025-05-07 · Analyzed
6.8EPSS 0.002
CVE-2019-12670
Cisco IOS XE Software IOx Guest Shell Namespace Protection Vulnerability
Published 2019-09-25 · Modified
6.7EPSS 0.003
CVE-2023-20109
A vulnerability in the Cisco Group Encrypted Transport VPN (GET VPN) feature of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker who has administrative control of either a group member or a key server to execute arbitrary code on an affected device or cause the device to crash. This vulnerability is due to insufficient validation of attributes in the Group Domain of Interpretation (GDOI) and G-IKEv2 protocols of the GET VPN feature. An attacker could exploit this vulnerability by either compromising an installed key server or modifying the configuration of a group member to point to a key server that is controlled by the attacker. A successful exploit could allow the attacker to execute arbitrary code and gain full control of the affected system or cause the affected system to reload, resulting in a denial of service (DoS) condition. For more information, see the Details ["#details"] section of this advisory.
Published 2023-09-27 · Analyzed
6.6KEVEPSS 0.023
CVE-2021-1385
Cisco IOx Application Environment Path Traversal Vulnerability
Published 2021-03-24 · Modified
6.5EPSS 0.027
CVE-2017-12232
A vulnerability in the implementation of a protocol in Cisco Integrated Services Routers Generation 2 (ISR G2) Routers running Cisco IOS 15.0 through 15.6 could allow an unauthenticated, adjacent attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to a misclassification of Ethernet frames. An attacker could exploit this vulnerability by sending a crafted Ethernet frame to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvc03809.
Published 2017-09-28 · Analyzed
6.5KEVEPSS 0.022
CVE-2017-6663
A vulnerability in the Autonomic Networking feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause autonomic nodes of an affected system to reload, resulting in a denial of service (DoS) condition. More Information: CSCvd88936. Known Affected Releases: Denali-16.2.1 Denali-16.3.1.
Published 2017-08-07 · Analyzed
6.5KEVEPSS 0.021
CVE-2017-12238
A vulnerability in the Virtual Private LAN Service (VPLS) code of Cisco IOS 15.0 through 15.4 for Cisco Catalyst 6800 Series Switches could allow an unauthenticated, adjacent attacker to cause a C6800-16P10G or C6800-16P10G-XL type line card to crash, resulting in a denial of service (DoS) condition. The vulnerability is due to a memory management issue in the affected software. An attacker could exploit this vulnerability by creating a large number of VPLS-generated MAC entries in the MAC address table of an affected device. A successful exploit could allow the attacker to cause a C6800-16P10G or C6800-16P10G-XL type line card to crash, resulting in a DoS condition. This vulnerability affects Cisco Catalyst 6800 Series Switches that are running a vulnerable release of Cisco IOS Software and have a Cisco C6800-16P10G or C6800-16P10G-XL line card in use with Supervisor Engine 6T. To be vulnerable, the device must also be configured with VPLS and the C6800-16P10G or C6800-16P10G-XL line card needs to be the core-facing MPLS interfaces. Cisco Bug IDs: CSCva61927.
Published 2017-09-28 · Analyzed
6.5KEVEPSS 0.020
CVE-2014-2146
The Zone-Based Firewall (ZBFW) functionality in Cisco IOS, possibly 15.4 and earlier, and IOS XE, possibly 3.13 and earlier, mishandles zone checking for existing sessions, which allows remote attackers to bypass intended resource-access restrictions via spoofed traffic that matches one of these sessions, aka Bug IDs CSCun94946 and CSCun96847.
Published 2016-09-22 · Modified
6.5EPSS 0.013
CVE-2016-6423
The IKEv2 client and initiator implementations in Cisco IOS 15.5(3)M and IOS XE allow remote IKEv2 servers to cause a denial of service (device reload) via crafted IKEv2 packets, aka Bug ID CSCux97540.
Published 2016-10-05 · Modified
6.5EPSS 0.012
CVE-2016-6412
The Cisco Application-hosting Framework (CAF) component in Cisco IOS 15.6(1)T1 and IOS XE, when the IOx feature set is enabled, allows man-in-the-middle attackers to trigger arbitrary downloads via crafted HTTP headers, aka Bug ID CSCuz84773.
Published 2016-09-24 · Modified
6.5EPSS 0.011
CVE-2018-0466
Cisco IOS and IOS XE Software OSPFv3 Denial of Service Vulnerability
Published 2018-10-05 · Modified
6.5EPSS 0.010
CVE-2018-0484
Cisco IOS and IOS XE Software Secure Shell Connection on VRF Vulnerability
Published 2019-01-10 · Modified
6.5EPSS 0.008
CVE-2016-1425
Cisco IOS 15.0(2)SG5, 15.1(2)SG3, 15.2(1)E, 15.3(3)S, and 15.4(1.13)S allows remote attackers to cause a denial of service (device crash) via a crafted LLDP packet, aka Bug ID CSCun66735.
Published 2016-07-03 · Modified
6.5EPSS 0.007
CVE-2016-6473
A vulnerability in Cisco IOS on Catalyst Switches and Nexus 9300 Series Switches could allow an unauthenticated, adjacent attacker to cause a Layer 2 network storm. More Information: CSCuu69332, CSCux07028. Known Affected Releases: 15.2(3)E. Known Fixed Releases: 12.2(50)SE4 12.2(50)SE5 12.2(50)SQ5 12.2(50)SQ6 12.2(50)SQ7 12.2(52)EY4 12.2(52)SE1 12.2(53)EX 12.2(53)SE 12.2(53)SE1 12.2(53)SE2 12.2(53)SG10 12.2(53)SG11 12.2(53)SG2 12.2(53)SG9 12.2(54)SG1 12.2(55)EX3 12.2(55)SE 12.2(55)SE1 12.2(55)SE10 12.2(55)SE2 12.2(55)SE3 12.2(55)SE4 12.2(55)SE5 12.2(55)SE6 12.2(55)SE7 12.2(55)SE8 12.2(55)SE9 12.2(58)EZ 12.2(58)SE1 12.2(58)SE2 12.2(60)EZ 12.2(60)EZ1 12.2(60)EZ2 12.2(60)EZ3 12.2(60)EZ4 12.2(60)EZ5 12.2(60)EZ6 12.2(60)EZ7 12.2(60)EZ8 15.0(1)EY2 15.0(1)SE 15.0(1)SE2 15.0(1)SE3 15.0(2)EA 15.0(2)EB 15.0(2)EC 15.0(2)ED 15.0(2)EH 15.0(2)EJ 15.0(2)EJ1 15.0(2)EK1 15.0(2)EX 15.0(2)EX1 15.0(2)EX3 15.0(2)EX4 15.0(2)EX5 15.0(2)EY 15.0(2)EY1 15.0(2)EY2 15.0(2)EZ 15.0(2)SE 15.0(2)SE1 15.0(2)SE2 15.0(2)SE3 15.0(2)SE4 15.0(2)SE5 15.0(2)SE6 15.0(2)SE7 15.0(2)SE9 15.0(2)SG10 15.0(2)SG3 15.0(2)SG6 15.0(2)SG7 15.0(2)SG8 15.0(2)SG9 15.0(2a)EX5 15.1(2)SG 15.1(2)SG1 15.1(2)SG2 15.1(2)SG3 15.1(2)SG4 15.1(2)SG5 15.1(2)SG6 15.2(1)E 15.2(1)E1 15.2(1)E2 15.2(1)E3 15.2(1)EY 15.2(2)E 15.2(2)E3 15.2(2b)E.
Published 2016-12-14 · Modified
6.5EPSS 0.006
CVE-2018-0163
A vulnerability in the 802.1x multiple-authentication (multi-auth) feature of Cisco IOS Software could allow an unauthenticated, adjacent attacker to bypass the authentication phase on an 802.1x multi-auth port. The vulnerability is due to a logic change error introduced into the code. An attacker could exploit this vulnerability by trying to access an 802.1x multi-auth port after a successful supplicant has authenticated. An exploit could allow the attacker to bypass the 802.1x access controls and obtain access to the network. Cisco Bug IDs: CSCvg69701.
Published 2018-03-28 · Modified
6.5EPSS 0.006
CVE-2018-0197
Cisco IOS and IOS XE Software VLAN Trunking Protocol Denial of Service Vulnerability
Published 2018-10-05 · Analyzed
6.5EPSS 0.006
CVE-2016-1424
Cisco IOS 15.2(1)T1.11 and 15.2(2)TST allows remote attackers to cause a denial of service (device crash) via a crafted LLDP packet, aka Bug ID CSCun63132.
Published 2016-06-19 · Modified
6.5EPSS 0.006
CVE-2017-6665
A vulnerability in the Autonomic Networking feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to reset the Autonomic Control Plane (ACP) of an affected system and view ACP packets that are transferred in clear text within an affected system, an Information Disclosure Vulnerability. More Information: CSCvd51214. Known Affected Releases: Denali-16.2.1 Denali-16.3.1.
Published 2017-08-07 · Modified
6.5EPSS 0.004
CVE-2025-20149
A vulnerability in the CLI of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, local attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to a buffer overflow. An attacker with a low-privileged account could exploit this vulnerability by using crafted commands at the CLI prompt. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.
Published 2025-09-24 · Analyzed
6.5EPSS 0.001
CVE-2011-0348
Cisco IOS 12.4(11)MD, 12.4(15)MD, 12.4(22)MD, 12.4(24)MD before 12.4(24)MD3, 12.4(22)MDA before 12.4(22)MDA5, and 12.4(24)MDA before 12.4(24)MDA3 on the Cisco Content Services Gateway Second Generation (aka CSG2) allows remote attackers to bypass intended access restrictions and intended billing restrictions by sending HTTP traffic to a restricted destination after sending HTTP traffic to an unrestricted destination, aka Bug ID CSCtk35917.
Published 2011-01-28 · Modified
6.4EPSS 0.023
CVE-2007-0917
The Intrusion Prevention System (IPS) feature for Cisco IOS 12.4XE to 12.3T allows remote attackers to bypass IPS signatures that use regular expressions via fragmented packets.
Published 2007-02-14 · Modified
6.4EPSS 0.019
CVE-2015-0669
The Autonomic Networking Infrastructure (ANI) implementation in Cisco IOS 15.4S and 15.4(3)S allows remote attackers to modify configuration settings or cause a denial of service (partial service outage) by sending crafted Autonomic Networking (AN) messages on an intranet network, aka Bug ID CSCup62167.
Published 2015-03-21 · Modified
6.4EPSS 0.017
CVE-2012-5032
The Flex-VPN load-balancing feature in the ipsec-ikev2 implementation in Cisco IOS before 15.1(1)SY3 does not require authentication, which allows remote attackers to trigger the forwarding of VPN traffic to an attacker-controlled destination, or the discarding of this traffic, by arranging for an arbitrary device to become a cluster member, aka Bug ID CSCub93641.
Published 2014-04-23 · Modified
6.4EPSS 0.013
CVE-2013-5552
Cisco IOS 12.4(24)MDB9 and earlier on Content Services Gateway (CSG) devices does not properly implement the "parse error drop" feature, which allows remote attackers to bypass intended access restrictions via a crafted series of packets, aka Bug ID CSCug90143.
Published 2013-11-13 · Modified
6.4EPSS 0.012
CVE-2018-0161
A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software running on certain models of Cisco Catalyst Switches could allow an authenticated, remote attacker to cause a denial of service (DoS) condition, aka a GET MIB Object ID Denial of Service Vulnerability. The vulnerability is due to a condition that could occur when the affected software processes an SNMP read request that contains a request for the ciscoFlashMIB object ID (OID). An attacker could trigger this vulnerability by issuing an SNMP GET request for the ciscoFlashMIB OID on an affected device. A successful exploit could cause the affected device to restart due to a SYS-3-CPUHOG. This vulnerability affects the following Cisco devices if they are running a vulnerable release of Cisco IOS Software and are configured to use SNMP Version 2 (SNMPv2) or SNMP Version 3 (SNMPv3): Cisco Catalyst 2960-L Series Switches, Cisco Catalyst Digital Building Series Switches 8P, Cisco Catalyst Digital Building Series Switches 8U. Cisco Bug IDs: CSCvd89541.
Published 2018-03-28 · Analyzed
6.3KEVEPSS 0.041
CVE-2015-0771
The IKE implementation in the WS-IPSEC-3 service module in Cisco IOS 12.2 on Catalyst 6500 devices allows remote authenticated users to cause a denial of service (device reload) by sending a crafted message during IPsec tunnel setup, aka Bug ID CSCur70505.
Published 2015-06-12 · Modified
6.3EPSS 0.024
CVE-2017-12211
A vulnerability in the IPv6 Simple Network Management Protocol (SNMP) code of Cisco IOS and Cisco IOS XE Software could allow an authenticated, remote attacker to cause high CPU usage or a reload of the device. The vulnerability is due to IPv6 sub block corruption. An attacker could exploit this vulnerability by polling the affected device IPv6 information. An exploit could allow the attacker to trigger high CPU usage or a reload of the device. Known Affected Releases: Denali-16.3.1. Cisco Bug IDs: CSCvb14640.
Published 2017-09-07 · Modified
6.3EPSS 0.016
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