CVE-2017-12240

CVE-2017-12240 affects Cisco IOS 12.2–15.6 and Cisco IOS XE DHCP relay subsystems. The issue is a buffer overflow in the DHCPv4 handling that allows unauthenticated, remote attackers to execute arbitrary code and possibly reload the device, causing a DoS. Impact is full control of the affected sy...

CVE-2018-0171

CVE-2018-0171 is a Cisco Smart Install remote code execution vulnerability in Cisco IOS/IOS XE where improper validation of packet data allows an unauthenticated, remote attacker to trigger a device reload (DoS) or execute arbitrary code by sending a crafted Smart Install message to TCP port 4786...

CVE-2017-3881

CVE-2017-3881 is a Cisco IOS/IOS XE vulnerability in the Cluster Management Protocol (CMP) handling. Two factors enable exploitation: (1) CMP-specific Telnet options were not restricted to internal cluster communications and could be processed over any Telnet session; (2) malformed CMP-specific T...

CVE-2017-6736

CVE-2017-6736 concerns Cisco IOS/IOS XE SNMP subsystem vulnerabilities caused by a buffer overflow. An authenticated remote attacker could remotely execute code or cause a reload by sending crafted SNMP packets over IPv4/IPv6. The issue affects SNMP versions 1/2c/3; for SNMPv2c you may need the r...

CVE-2018-0167

CVE-2018-0167 involves multiple buffer overflow vulnerabilities in the Link Layer Discovery Protocol (LLDP) subsystem of Cisco IOS Software, IOS XE Software, and IOS XR Software. The description documents that an unauthenticated, adjacent attacker could trigger a denial of service or escalate pri...

CVE-2018-0161

The CVE-2018-0161 issue is a Cisco IOS/IOS XE SNMP vulnerability affecting Cisco Catalyst switches (e.g., 2960-L series and related Digital Building Series switches) where an authenticated SNMP GET for the ciscoFlashMIB OID can trigger a DoS and restart the device (SYS-3-CPUHOG). Root cause is a ...

CVE-2018-0175

CVE-2018-0175 is a vulnerability in the LLDP subsystem of Cisco IOS Software, IOS XE Software, and IOS XR Software. The issue stems from a Format String vulnerability in LLDP that could allow an unauthenticated, adjacent attacker to cause a denial of service or to execute arbitrary code with elev...

CVE-2017-6737

CVE-2017-6737 is a Cisco SNMP remote code execution vulnerability affecting the SNMP subsystem in Cisco IOS and IOS XE. The issue arises from a buffer overflow in the SNMP handling code that could allow an authenticated, remote attacker to execute arbitrary code or cause a system reload by sendin...

CVE-2017-6743

Cisco IOS and IOS XE SNMP Remote Code Execution Vulnerabilities (CVE-2017-6743) arise from buffer overflow in the SNMP subsystem, allowing an authenticated, remote attacker to execute arbitrary code or cause a reload by sending crafted SNMP packets over IPv4/IPv6. Exploitation varies by SNMP vers...

CVE-2018-0172

CVE-2018-0172 affects Cisco IOS/IOS XE. The issue lies in the DHCP option 82 encapsulation in DHCPv4, where incomplete input validation can lead to a heap overflow and device reload, causing DoS. An unauthenticated, remote attacker could trigger this by sending crafted DHCPv4 packets. Documents n...

CVE-2017-6738

Cisco IOS and IOS XE SNMP subsystem contains multiple buffer overflow vulnerabilities that could allow an authenticated, remote attacker to execute arbitrary code or cause a reload via crafted SNMP packets over IPv4/IPv6. Affected are SNMP versions 1–3; for SNMPv2c/earlier, attacker needs the rea...

CVE-2017-6740

CVE-2017-6740 describes multiple SNMP remote code execution vulnerabilities in Cisco IOS and IOS XE, due to a buffer overflow in the SNMP subsystem. An authenticated, remote attacker could exploit crafted SNMP packets (over IPv4/IPv6) to execute arbitrary code or cause a reload. Exploitation for ...

CVE-2017-12237

CVE-2017-12237 affects Cisco IOS (15.0–15.6) and IOS XE (3.5–16.5) with ISAKMP enabled. The IKEv2 module is vulnerable to unauthenticated remote probes via specific IKEv2 packets, allowing high CPU utilization, traceback messages, or device reloads that cause DoS. Affected devices need ISAKMP to ...

CVE-2017-6744

CVE-2017-6744 is a Cisco IOS/IOS XE SNMP remote code execution vulnerability caused by a buffer overflow in the SNMP subsystem. An authenticated, remote attacker could exploit this by sending a crafted SNMP packet over IPv4/IPv6 to affected devices, potentially executing arbitrary code or causing...

CVE-2018-0158

CVE-2018-0158 affects Cisco IOS/IOS XE with an issue in the IKEv2 processing path. The vulnerability can be triggered by crafted IKEv2 packets from an unauthenticated, remote attacker, potentially causing a memory leak or device reload and resulting in a DoS condition. Connected sources corrobora...

CVE-2018-0173

CVE-2018-0173 affects Cisco IOS Software and Cisco IOS XE Software. The issue is incomplete input validation of encapsulated DHCPv4 option 82 information, processed when handling DHCPOFFER responses forwarded to DHCP servers. A crafted DHCPv4 packet can trigger an error in processing the option 8...

CVE-2017-6663

CVE-2017-6663 relates to Cisco IOS/IOS XE Autonomic Networking. The flaw allows an unauthenticated, adjacent attacker to trigger a reload of autonomic nodes, causing a DoS condition. Affected products include Cisco IOS Software and Cisco IOS XE Software with Autonomic Networking enabled (per Dena...

CVE-2017-6739

CVE-2017-6739 describes a Cisco IOS/IOS XE SNMP subsystem vulnerability where a buffer overflow in SNMP handling can allow an authenticated, remote attacker to either reload the device or execute arbitrary code. Affected are Cisco devices running IOS/IOS XE with SNMP enabled; exploitation require...

CVE-2018-0156

CVE-2018-0156 concerns Cisco IOS/IOS XE Smart Install DoS. The vulnerability arises from improper validation of Smart Install packet data, allowing an unauthenticated, remote attacker to trigger a device reload via a crafted packet sent to TCP port 4786. Affected are Cisco devices configured as S...

CVE-2017-6627

CVE-2017-6627 affects Cisco IOS 15.1/15.2/15.4 and IOS XE 3.14–3.18. A UDP processing code issue leaves UDP sockets idle, allowing unauthenticated remote attackers to send UDP packets (dest port 0) that fill the input interface queue, wedge an interface queue, and cause DoS. The input queue repor...

CVE-2018-0174

CVE-2018-0174 affects Cisco IOS/IOS XE DHCP option 82 encapsulation. The issue is incomplete input validation of DHCPv4 option 82 data received from DHCP relay agents, allowing an unauthenticated, remote attacker to cause an affected device to reload and trigger a DoS. The connected documents con...

CVE-2017-12232

Cisco ISR G2 routers running Cisco IOS 15.0–15.6 are affected by CVE-2017-12232 due to a misclassification of Ethernet frames, which allows an unauthenticated adjacent attacker to cause a reload and a DoS condition by sending a crafted Ethernet frame. The vulnerability impact is a denial of servi...

CVE-2017-12233

Summary: CVE-2017-12233 affects Cisco IOS (versions 12.4–15.6) where CIP (Common Industrial Protocol) packets are improperly parsed. The root cause is insufficient input handling for CIP requests, allowing an unauthenticated, remote attacker to cause an affected device to reload, producing a deni...

CVE-2018-0154

CVE-2018-0154 affects the Cisco IOS ISM‑VPN crypto engine. The issue stems from improper handling of VPN traffic, allowing an unauthenticated, remote attacker to trigger a DoS via crafted VPN traffic that can cause the device to hang or crash. Affected product: Cisco Integrated Services Module fo...

CVE-2017-12319

Cisco IOS XE Software EVPN BGP vulnerability CVE-2017-12319 allows an unauthenticated remote attacker to trigger a reload or BGP routing-table corruption, causing DoS. Root cause: changes in the BGP MPLS-Based EVPN RFC 7432 draft lead to miscalculation of the IP address length field when processi...

CVE-2017-12238

Cisco IOS on Catalyst 6800 Series switches (Cisco 6800-16P10G/16P10G-XL with Supervisor Engine 6T) is affected by CVE-2017-12238. The vulnerability stems from a memory management flaw in the VPLS code, exploitable by an unauthenticated, adjacent attacker who can flood the MAC address table with V...

CVE-2018-0155

CVE-2018-0155 affects Cisco Catalyst 4500/4500-X switches where the BFD offload has insufficient error handling for incomplete BFD headers. An unauthenticated remote attacker can send crafted BFD messages to trigger a crash in the iosd process and potentially cause system reloads, resulting in Do...

CVE-2017-12231

Cisco IOS NAT denial-of-service vulnerability (CVE-2017-12231) affects IOS 12.4–15.6 where NAT ALG improperly translates H.323 RAS messages, allowing unauthenticated remote DoS via crafted IPv4 packets. Affected devices using NAT ALG for H.323 RAS messages can crash and reload. Exploitation detai...

CVE-2017-12235

The CVE-2017-12235 issue is a DoS flaw in Cisco IOS Software’s PROFINET Discovery and Configuration Protocol (PN-DCP) handling. It affects Cisco IOS on devices configured to process PN-DCP (notably Cisco Industrial Ethernet Switches) and stems from improper parsing of PN-DCP Identify Request pack...

CVE-2018-0180

Cisco IOS Software CVE-2018-0180 describes multiple DoS vulnerabilities in the Login Enhancements (Login Block) feature, enabling an unauthenticated, remote attacker to trigger a device reload. Affected are Cisco devices running IOS releases 15.4(2)T, 15.4(3)M, or 15.4(2)CG and later. The root ca...

CVE-2018-0179

CVE-2018-0179 describes DoS in Cisco IOS Software due to vulnerabilities in the Login Enhancements (Login Block) feature. Affected are Cisco IOS releases 15.4(2)T, 15.4(3)M, 15.4(2)CG and later. An unauthenticated, remote attacker can trigger a device reload, causing DoS. The connected Cisco advi...

CVE-2018-0159

CVE-2018-0159 affects Cisco IOS/IOS XE: IKEv1 implementation vulnerability where improper validation of specific IKEv1 packets allows an unauthenticated, remote attacker to reload an affected device, causing DoS during IKE negotiation. Root cause: packet validation flaw in IKEv1 handling. Impact:...

CVE-2017-12234

CVE-2017-12234 affects Cisco IOS Software CIP implementation (versions 12.4–15.6). The issue stems from improper parsing of crafted CIP packets, allowing an unauthenticated, remote attacker to cause the device to reload and trigger DoS. Affected components are Cisco IOS/CIP handling; exploit reli...

CVE-1999-0524

CVE-1999-0524 is an ICMP information-disclosure vulnerability where ICMP replies reveal (1) netmask and (2) timestamp to arbitrary hosts. Connected reports link it to multiple products (e.g., Nutanix AHV advisories NXSA‑AHV series and ABB M2M Gateway plugin) and describe the issue as an informati...

CVE-2017-6742

CVE-2017-6742 is a Cisco SNMP remote code execution vulnerability in the SNMP stack of IOS/IOS XE. A stack-based overflow could allow an authenticated attacker to run arbitrary code or cause a reload by sending crafted SNMP packets (targets SNMP v1/v2c/v3; needs read-only community string or v3 c...

CVE-2016-6415

CVE-2016-6415 is an information-disclosure vulnerability in Cisco IOS, IOS XE, IOS XR (and PIX prior to 7.0) where the IKEv1 security-negotiation code lacks sufficient checks, enabling an unauthenticated remote attacker to read memory contents via an SA negotiation request. Affected products span...

CVE-2025-20352

CVE-2025-20352 concerns Cisco IOS/IOS XE SNMP subsystem. A stack-based buffer overflow could allow a low-privileged, authenticated remote attacker to cause a DoS (reload) or, with higher privileges, execute arbitrary code as root on affected devices. Exploitation requires SNMP credentials (v2c/v1...

CVE-2004-1464

Cisco IOS Denial-of-Service vulnerability CVE-2004-1464 affects Cisco IOS 12.2(15) and earlier. A specially crafted TCP connection to the Telnet or reverse Telnet port can cause the device to refuse VTY connections, resulting in DoS. Affected component: Telnet service on IOS; root cause is the cr...

CVE-2008-4609

CVE-2008-4609 is a TCP state-exhaustion DoS vulnerability demonstrated by sockstress. It was described as affecting the TCP implementation in Linux, BSD-based platforms, Windows, Cisco products, and probably others. The issue enables a remote attacker to exhaust connection state, potentially rend...

CVE-2023-20109

CVE-2023-20109 affects Cisco IOS and IOS XE GET VPN. Root cause: insufficient validation of GDOI/G-IKEv2 attributes in GET VPN, enabling an authenticated admin on a group member or key server to execute arbitrary code or crash the device. Impact (as stated): full device control or reboot/DoS. Rem...

CVE-2025-20363

CVE-2025-20363 affects Cisco Secure Firewall ASA/FTD web services and several Cisco IOS families. The issue arises from improper validation of user-supplied input in HTTP requests, allowing an unauthenticated remote attacker (ASA/FTD) or an authenticated, low-privilege remote attacker (IOS/IOS XE...

CVE-2026-20301

CVE-2026-20301 affects Cisco IOS Software and Cisco IOS XE Software via the Extensible Messaging Client Protocol (XMCP / External Client protocol). The flaw is improper handling of malformed XMCP packets, enabling an unauthenticated, remote attacker to trigger a device reload and cause a DoS. The...

CVE-2026-20012

The CVE-2026-20012 entry describes a memory-leak DoS in the IKEv2 handling of Cisco IOS, IOS XE, ASA, and FTDS (Threat Defense). Root cause: improper parsing of IKEv2 packets leading to conditions where devices reload (IOS/IOS XE) or exhaust memory to the point of instability (ASA/FTD). Affected ...

CVE-2020-3204

CVE-2020-3204 affects Cisco IOS and IOS XE Tcl interpreter. The vulnerability arises from insufficient input validation of data passed to Tcl, allowing an authenticated, local attacker with privileged EXEC credentials to execute arbitrary code on the underlying OS with root privileges. Impact is ...

CVE-2003-0567

Cisco IOS 11.x and 12.0–12.2 are affected by CVE-2003-0567. By sending a specific sequence of IPv4 packets to a router’s interface, an attacker can cause the input queue to become full and trigger a denial of service, potentially stopping traffic processing on that interface and affecting related...

CVE-2013-0149

CVE-2013-0149: The OSPF implementation in Cisco IOS (12.0–12.4, 15.0–15.3), IOS-XE 2.x–3.9.xS, ASA/PIX 7.x–9.1, FWSM, NX-OS, and StarOS before 14.0.50488 fails to properly validate LSA type 1 packets before updating the LSA database, enabling remote attackers to cause a denial of service (routing...

CVE-2001-0537

CVE-2001-0537 affects Cisco IOS HTTP Server in Cisco IOS 11.3–12.2. The vulnerability allows bypassing local authentication and executing arbitrary commands by specifying a high access level in the URL. Impact is authenticated command execution with full privileges on affected devices. Public det...

CVE-2022-20920

CVE-2022-20920 affects Cisco IOS Software and Cisco IOS XE Software. It is a DoS vulnerability in the SSH implementation caused by improper resource handling during exceptional conditions. A remote, authenticated attacker can repeatedly connect and send specific SSH requests to force a device rel...

CVE-2024-20433

Cisco IOS and IOS XE Software are affected by CVE-2024-20433 due to a buffer overflow in the RSVP processing path. An unauthenticated, remote attacker can send crafted RSVP packets to cause the device to reload, yielding a DoS condition. Cisco’s advisory and multiple vendor/NVD records confirm th...

CVE-2019-1747

CVE-2019-1747 affects Cisco IOS and IOS XE SMS handling. The issue arises from improper processing of SMS PDUs encoded with a special character set, enabling an unauthenticated, remote attacker to trigger a denial-of-service on affected devices. Exploitation would crash the wireless WAN (WWAN) ce...