A vulnerability in the web server authentication of Cisco IOS XE Software could allow an authenticated, remote attacker to crash the web server on the device. The vulnerability is due to insufficient input validation during authentication. An attacker could exploit this vulnerability by entering unexpected characters during a valid authentication. A successful exploit could allow the attacker to crash the web server on the device, which must be manually recovered by disabling and re-enabling the web server.
A vulnerability in the Polaris kernel of Cisco Catalyst 9200 Series Switches could allow an unauthenticated, remote attacker to crash the device. The vulnerability is due to insufficient packet size validation. An attacker could exploit this vulnerability by sending jumbo frames or frames larger than the configured MTU size to the management interface of this device. A successful exploit could allow the attacker to crash the device fully before an automatic recovery.
A vulnerability in Cisco IOS XE SD-WAN Software could allow an unauthenticated, local attacker to gain unauthorized access to an affected device. The vulnerability is due to the existence of default credentials within the default configuration of an affected device. An attacker who has access to an affected device could log in with elevated privileges. A successful exploit could allow the attacker to take complete control of the device. This vulnerability affects Cisco devices that are running Cisco IOS XE SD-WAN Software releases 16.11 and earlier.
A vulnerability in the CLI of Cisco IOS XE Software could allow an authenticated, local attacker to write values to the underlying memory of an affected device. The vulnerability is due to improper input validation and authorization of specific commands that a user can execute within the CLI. An attacker could exploit this vulnerability by authenticating to an affected device and issuing a specific set of commands. A successful exploit could allow the attacker to modify the configuration of the device to cause it to be non-secure and abnormally functioning.
A vulnerability in the Guest Shell of Cisco IOS XE Software could allow an authenticated, local attacker to perform directory traversal on the base Linux operating system of Cisco IOS XE Software. The vulnerability is due to incomplete validation of certain commands. An attacker could exploit this vulnerability by first accessing the Guest Shell and then entering specific commands. A successful exploit could allow the attacker to execute arbitrary code on the base Linux operating system.
A vulnerability in the logic that handles access control to one of the hardware components in Cisco's proprietary Secure Boot implementation could allow an authenticated, local attacker to write a modified firmware image to the component. This vulnerability affects multiple Cisco products that support hardware-based Secure Boot functionality. The vulnerability is due to an improper check on the area of code that manages on-premise updates to a Field Programmable Gate Array (FPGA) part of the Secure Boot hardware implementation. An attacker with elevated privileges and access to the underlying operating system that is running on the affected device could exploit this vulnerability by writing a modified firmware image to the FPGA. A successful exploit could either cause the device to become unusable (and require a hardware replacement) or allow tampering with the Secure Boot verification process, which under some circumstances may allow the attacker to install and boot a malicious software image. An attacker will need to fulfill all the following conditions to attempt to exploit this vulnerability: Have privileged administrative access to the device. Be able to access the underlying operating system running on the device; this can be achieved either by using a supported, documented mechanism or by exploiting another vulnerability that would provide an attacker with such access. Develop or have access to a platform-specific exploit. An attacker attempting to exploit this vulnerability across multiple affected platforms would need to research each one of those platforms and then develop a platform-specific exploit. Although the research process could be reused across different platforms, an exploit developed for a given hardware platform is unlikely to work on a different hardware platform.
A vulnerability in the Hot Standby Router Protocol (HSRP) subsystem of Cisco IOS and IOS XE Software could allow an unauthenticated, adjacent attacker to receive potentially sensitive information from an affected device. The vulnerability is due to insufficient memory initialization. An attacker could exploit this vulnerability by receiving HSRPv2 traffic from an adjacent HSRP member. A successful exploit could allow the attacker to receive potentially sensitive information from the adjacent device.
A vulnerability in the Cluster Management Protocol (CMP) processing code in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to trigger a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient input validation when processing CMP management packets. An attacker could exploit this vulnerability by sending malicious CMP management packets to an affected device. A successful exploit could cause the switch to crash, resulting in a DoS condition. The switch will reload automatically.
A vulnerability in the Easy Virtual Switching System (VSS) of Cisco IOS XE Software on Catalyst 4500 Series Switches could allow an unauthenticated, adjacent attacker to cause the switches to reload. The vulnerability is due to incomplete error handling when processing Cisco Discovery Protocol (CDP) packets used with the Easy Virtual Switching System. An attacker could exploit this vulnerability by sending a specially crafted CDP packet. An exploit could allow the attacker to cause the device to reload, resulting in a denial of service (DoS) condition.
A vulnerability in the VLAN Trunking Protocol (VTP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to corrupt the internal VTP database on an affected device and cause a denial of service (DoS) condition. The vulnerability is due to a logic error in how the affected software handles a subset of VTP packets. An attacker could exploit this vulnerability by sending VTP packets in a sequence that triggers a timeout in the VTP message processing code of the affected software. A successful exploit could allow the attacker to impact the ability to create, modify, or delete VLANs and cause a DoS condition. There are workarounds that address this vulnerability. This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS Software or Cisco IOS XE Software, are operating in VTP client mode or VTP server mode, and do not have a VTP domain name configured. The default configuration for Cisco devices that are running Cisco IOS Software or Cisco IOS XE Software and support VTP is to operate in VTP server mode with no domain name configured.