VendorsCiscoiosall versions
Vulnerabilities

Cisco IOS

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

620CVEs
CVE-2003-0305
The Service Assurance Agent (SAA) in Cisco IOS 12.0 through 12.2, aka Response Time Reporter (RTR), allows remote attackers to cause a denial of service (crash) via malformed RTR packets to port 1967.
Published 2003-05-17 · Modified
5.0EPSS 0.013
CVE-2012-4658
The ios-authproxy implementation in Cisco IOS before 15.1(1)SY3 allows remote attackers to cause a denial of service (webauth and HTTP service outage) via vectors that trigger incorrectly terminated HTTP sessions, aka Bug ID CSCtz99447.
Published 2014-04-23 · Modified
5.0EPSS 0.013
CVE-2014-3268
Cisco IOS 15.2(4)M4 on Cisco Unified Border Element (CUBE) devices allows remote attackers to cause a denial of service (input-queue consumption and traffic-processing outage) via crafted RTCP packets, aka Bug ID CSCuj72215.
Published 2014-05-20 · Modified
5.0EPSS 0.012
CVE-2012-3915
The DMVPN tunnel implementation in Cisco IOS 15.2 allows remote attackers to cause a denial of service (persistent IKE state) via a large volume of hub-to-spoke traffic, aka Bug ID CSCtq39602.
Published 2012-09-16 · Modified
5.0EPSS 0.012
CVE-2011-4015
Cisco IOS 15.2S allows remote attackers to cause a denial of service (interface queue wedge) via malformed UDP traffic on port 465, aka Bug ID CSCts48300.
Published 2012-05-02 · Modified
5.0EPSS 0.012
CVE-1999-0445
In Cisco routers under some versions of IOS 12.0 running NAT, some packets may not be filtered by input access list filters.
Published 1999-09-29 · Modified
5.0EPSS 0.011
CVE-1999-0159
Attackers can crash a Cisco IOS router or device, provided they can get to an interactive prompt (such as a login). This applies to some IOS 9.x, 10.x, and 11.x releases.
Published 1999-09-29 · Modified
5.0EPSS 0.011
CVE-1999-0157
Cisco PIX firewall and CBAC IP fragmentation attack results in a denial of service.
Published 1999-09-29 · Modified
5.0EPSS 0.011
CVE-2015-0659
The Autonomic Networking Infrastructure (ANI) implementation in Cisco IOS allows remote attackers to trigger self-referential adjacencies via a crafted Autonomic Networking (AN) message, aka Bug ID CSCup62157.
Published 2015-03-06 · Modified
5.0EPSS 0.011
CVE-1999-0230
Buffer overflow in Cisco 7xx routers through the telnet service.
Published 1999-09-29 · Modified
5.0EPSS 0.011
CVE-2012-0339
Cisco IOS 12.2 through 12.4 and 15.0 does not recognize the vrf-also keyword during enforcement of access-class commands, which allows remote attackers to establish TELNET connections from arbitrary source IP addresses via a standard TELNET client, aka Bug ID CSCsi77774.
Published 2012-05-02 · Modified
5.0EPSS 0.010
CVE-2015-0606
The IOS Shell in Cisco IOS allows local users to cause a denial of service (device crash) via unspecified commands, aka Bug ID CSCur59696.
Published 2015-02-12 · Modified
4.9EPSS 0.003
CVE-2012-4638
Cisco IOS before 15.1(1)SY allows local users to cause a denial of service (device reload) by establishing an outbound SSH session, aka Bug ID CSCto00318.
Published 2014-04-23 · Modified
4.9EPSS 0.003
CVE-2022-20661
Cisco Catalyst Digital Building Series Switches and Cisco Catalyst Micro Switches Vulnerabilities
Published 2022-04-15 · Modified
4.9EPSS 0.002
CVE-2019-12668
Cisco IOS and IOS XE Software Stored Banner Cross-Site Scripting Vulnerability
Published 2019-09-25 · Modified
4.8EPSS 0.008
CVE-2004-0244
Cisco 6000, 6500, and 7600 series systems with Multilayer Switch Feature Card 2 (MSFC2) and a FlexWAN or OSM module allow local users to cause a denial of service (hang or reset) by sending a layer 2 frame packet that encapsulates a layer 3 packet, but has inconsistent length values with that packet.
Published 2004-03-18 · Modified
4.71 PoCEPSS 0.011
CVE-2019-1758
Cisco IOS Software Catalyst 6500 Series 802.1x Authentication Bypass Vulnerability
Published 2019-03-28 · Modified
4.7EPSS 0.006
CVE-2017-3803
A vulnerability in the Cisco IOS Software forwarding queue of Cisco 2960X and 3750X switches could allow an unauthenticated, adjacent attacker to cause a memory leak in the software forwarding queue that would eventually lead to a partial denial of service (DoS) condition. More Information: CSCva72252. Known Affected Releases: 15.2(2)E3 15.2(4)E1. Known Fixed Releases: 15.2(2)E6 15.2(4)E3 15.2(5)E1 15.2(5.3.28i)E1 15.2(6.0.49i)E 3.9(1)E.
Published 2017-01-26 · Modified
4.7EPSS 0.006
CVE-2020-3231
Cisco IOS Software for Catalyst 2960-L Series Switches and Catalyst CDB-8P Switches 802.1X Authentication Bypass Vulnerability
Published 2020-06-03 · Modified
4.7EPSS 0.005
CVE-2025-20137
A vulnerability in the access control list (ACL) programming of Cisco IOS Software that is running on Cisco Catalyst 1000 Switches and Cisco Catalyst 2960L Switches could allow an unauthenticated, remote attacker to bypass a configured ACL. This vulnerability is due to the use of both an IPv4 ACL and a dynamic ACL of IP Source Guard on the same interface, which is an unsupported configuration. An attacker could exploit this vulnerability by attempting to send traffic through an affected device. A successful exploit could allow the attacker to bypass an ACL on the affected device. Note: Cisco documentation has been updated to reflect that this is an unsupported configuration. However, Cisco is publishing this advisory because the device will not prevent an administrator from configuring both features on the same interface. There are no plans to implement the ability to configure both features on the same interface on Cisco Catalyst 1000 or Catalyst 2960L Switches.
Published 2025-05-07 · Analyzed
4.7EPSS 0.003
CVE-2006-0486
Certain Cisco IOS releases in 12.2S based trains with maintenance release number 25 and later, 12.3T based trains, and 12.4 based trains reuse a Tcl Shell process across login sessions of different local users on the same terminal if the first user does not use tclquit before exiting, which may cause subsequent local users to execute unintended commands or bypass AAA command authorization checks, aka Bug ID CSCef77770.
Published 2006-02-01 · Modified
4.6EPSS 0.004
CVE-2006-0485
The TCL shell in Cisco IOS 12.2(14)S before 12.2(14)S16, 12.2(18)S before 12.2(18)S11, and certain other releases before 25 January 2006 does not perform Authentication, Authorization, and Accounting (AAA) command authorization checks, which may allow local users to execute IOS EXEC commands that were prohibited via the AAA configuration, aka Bug ID CSCeh73049.
Published 2006-02-01 · Modified
4.6EPSS 0.004
CVE-2012-5037
The ACL implementation in Cisco IOS before 15.1(1)SY on Catalyst 6500 and 7600 devices allows local users to cause a denial of service (device reload) via a "no object-group" command followed by an object-group command, aka Bug ID CSCts16133.
Published 2014-04-23 · Modified
4.6EPSS 0.003
CVE-2013-1136
The crypto engine process in Cisco IOS on Aggregation Services Router (ASR) Route Processor 2 does not properly manage memory, which allows local users to cause a denial of service (route processor crash) by creating multiple tunnels and then examining encryption statistics, aka Bug ID CSCuc52193.
Published 2013-05-13 · Modified
4.6EPSS 0.002
CVE-2017-12289
A vulnerability in conditional, verbose debug logging for the IPsec feature of Cisco IOS XE Software could allow an authenticated, local attacker to display sensitive IPsec information in the system log file. The vulnerability is due to incorrect implementation of IPsec conditional, verbose debug logging that causes sensitive information to be written to the log file. This information should be restricted. An attacker who has valid administrative credentials could exploit this vulnerability by authenticating to the device and enabling conditional, verbose debug logging for IPsec and viewing the log file. An exploit could allow the attacker to access sensitive information related to the IPsec configuration. Cisco Bug IDs: CSCvf12081.
Published 2017-10-19 · Modified
4.4EPSS 0.004
CVE-2019-1762
Cisco IOS and IOS XE Software Information Disclosure Vulnerability
Published 2019-03-28 · Modified
4.4EPSS 0.002
CVE-2009-1220
Cross-site scripting (XSS) vulnerability in +webvpn+/index.html in WebVPN on the Cisco Adaptive Security Appliances (ASA) 5520 with software 7.2(4)30 and earlier 7.2 versions including 7.2(2)22, and 8.0(4)28 and earlier 8.0 versions, when clientless mode is enabled, allows remote attackers to inject arbitrary web script or HTML via the Host HTTP header.
Published 2009-04-01 · Modified
4.31 PoCEPSS 0.090
CVE-2008-3821
Multiple cross-site scripting (XSS) vulnerabilities in the HTTP server in Cisco IOS 11.0 through 12.4 allow remote attackers to inject arbitrary web script or HTML via (1) the query string to the ping program or (2) unspecified other aspects of the URI.
Published 2009-01-16 · Modified
4.31 PoCEPSS 0.054
CVE-2009-0470
Multiple cross-site scripting (XSS) vulnerabilities in the HTTP server in Cisco IOS 12.4(23) allow remote attackers to inject arbitrary web script or HTML via the PATH_INFO to the default URI under (1) level/15/exec/-/ or (2) exec/, a different vulnerability than CVE-2008-3821.
Published 2009-02-06 · Modified
4.31 PoCEPSS 0.044
CVE-2004-0589
Cisco IOS 11.1(x) through 11.3(x) and 12.0(x) through 12.2(x), when configured for BGP routing, allows remote attackers to cause a denial of service (device reload) via malformed BGP (1) OPEN or (2) UPDATE messages.
Published 2004-06-23 · Modified
4.3EPSS 0.030
CVE-2009-2862
The Object Groups for Access Control Lists (ACLs) feature in Cisco IOS 12.2XNB, 12.2XNC, 12.2XND, 12.4MD, 12.4T, 12.4XZ, and 12.4YA allows remote attackers to bypass intended access restrictions via crafted requests, aka Bug IDs CSCsx07114, CSCsu70214, CSCsw47076, CSCsv48603, CSCsy54122, and CSCsu50252.
Published 2009-09-28 · Modified
4.3EPSS 0.023
CVE-2015-0607
The Authentication Proxy feature in Cisco IOS does not properly handle invalid AAA return codes from RADIUS and TACACS+ servers, which allows remote attackers to bypass authentication in opportunistic circumstances via a connection attempt that triggers an invalid code, as demonstrated by a connection attempt with a blank password, aka Bug IDs CSCuo09400 and CSCun16016.
Published 2015-03-06 · Modified
4.3EPSS 0.020
CVE-2014-3262
The Locator/ID Separation Protocol (LISP) implementation in Cisco IOS 15.3(3)S and earlier and IOS XE does not properly validate parameters in ITR control messages, which allows remote attackers to cause a denial of service (CEF outage and packet drops) via malformed messages, aka Bug ID CSCun73782.
Published 2014-05-16 · Modified
4.3EPSS 0.016
CVE-2012-1361
Cisco IOS 15.1 and 15.2, when the Multicast Music-on-Hold (MMoH) feature of Cisco Unified Communications Manager (CUCM) is enabled, allows remote attackers to obtain sensitive crosstalk information by listening during a PSTN call, aka Bug ID CSCtx77750.
Published 2012-08-06 · Modified
4.3EPSS 0.015
CVE-2015-0610
Race condition in the object-group ACL feature in Cisco IOS 15.5(2)T and earlier allows remote attackers to bypass intended access restrictions via crafted network traffic that triggers improper handling of the timing of process switching and Cisco Express Forwarding (CEF) switching, aka Bug ID CSCun21071.
Published 2015-02-12 · Modified
4.3EPSS 0.014
CVE-2007-5547
Cross-site scripting (XSS) vulnerability in Cisco IOS allows remote attackers to inject arbitrary web script or HTML, and execute IOS commands, via unspecified vectors, aka PSIRT-2022590358. NOTE: as of 20071016, the only disclosure is a vague pre-advisory with no actionable information. However, since it is from a well-known researcher, it is being assigned a CVE identifier for tracking purposes.
Published 2007-10-18 · Modified
4.3EPSS 0.013
CVE-2012-0362
The extended ACL functionality in Cisco IOS 12.2(58)SE2 and 15.0(1)SE discards all lines that end with a log or time keyword, which allows remote attackers to bypass intended access restrictions in opportunistic circumstances by sending network traffic, aka Bug ID CSCts01106.
Published 2012-05-02 · Modified
4.3EPSS 0.013
CVE-2013-5548
The IKEv2 implementation in Cisco IOS, when AES-GCM or AES-GMAC is used, allows remote attackers to bypass certain IPsec anti-replay features via IPsec tunnel traffic, aka Bug ID CSCuj47795.
Published 2013-11-01 · Modified
4.3EPSS 0.011
CVE-2012-3918
Cisco IOS before 15.3(1)T on Cisco 2900 devices, when a VWIC2-2MFT-T1/E1 card is configured for TDM/HDLC mode, allows remote attackers to cause a denial of service (serial-interface outage) via certain Frame Relay traffic, aka Bug ID CSCub13317.
Published 2014-04-23 · Modified
4.3EPSS 0.011
CVE-2012-4651
Cisco IOS before 15.3(2)T, when scansafe is enabled, allows remote attackers to cause a denial of service (latency) via SYN packets that are not accompanied by SYN-ACK packets from the Scan Safe Tower, aka Bug ID CSCub85451.
Published 2014-04-23 · Modified
4.3EPSS 0.011
← Prev15 / 16Next →