Layer 2 network filtering capabilities such as IPv6 RA guard or ARP inspection can be bypassed using combinations of VLAN 0 headers and LLC/SNAP headers.
A vulnerability in the DHCP snooping feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to a crafted IPv4 DHCP request packet being mishandled when endpoint analytics are enabled. An attacker could exploit this vulnerability by sending a crafted DHCP request through an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. Note: The attack vector is listed as network because a DHCP relay anywhere on the network could allow exploits from networks other than the adjacent one.
A vulnerability in the application-hosting subsystem of Cisco IOS XE Software could allow an authenticated, local attacker to elevate privileges to root on an affected device. The attacker could execute IOS XE commands outside the application-hosting subsystem Docker container as well as on the underlying Linux operating system. These commands could be run as the root user. The vulnerability is due to a combination of two factors: (a) incomplete input validation of the user payload of CLI commands, and (b) improper role-based access control (RBAC) when commands are issued at the command line within the application-hosting subsystem. An attacker could exploit this vulnerability by using a CLI command with crafted user input. A successful exploit could allow the lower-privileged attacker to execute arbitrary CLI commands with root privileges. The attacker would need valid user credentials to exploit this vulnerability.
A vulnerability in the file system permissions of Cisco IOS XE Software could allow an authenticated, local attacker to obtain read and write access to critical configuration or system files. The vulnerability is due to insufficient file system permissions on an affected device. An attacker could exploit this vulnerability by connecting to an affected device's guest shell, and accessing or modifying restricted files. A successful exploit could allow the attacker to view or modify restricted information or configurations that are normally not accessible to system administrators.
Multiple vulnerabilities in the web-based user interface (Web UI) of Cisco IOS XE Software could allow an authenticated, remote attacker to execute commands with elevated privileges on the affected device. For more information about these vulnerabilities, see the Details section of this advisory.
A vulnerability in the processing of boot options of specific Cisco IOS XE Software switches could allow an authenticated, local attacker with root shell access to the underlying operating system (OS) to conduct a command injection attack during device boot. This vulnerability is due to insufficient input validation checks while processing boot options. An attacker could exploit this vulnerability by modifying device boot options to execute attacker-provided code. A successful exploit may allow an attacker to bypass the Secure Boot process and execute malicious code on an affected device with root-level privileges.
A vulnerability in Cisco IOS XE Software could allow an authenticated, local attacker to escalate their privileges to a user with root-level privileges. The vulnerability is due to insufficient validation of user-supplied content. This vulnerability could allow an attacker to load malicious software onto an affected device.
A vulnerability in the PROFINET handler for Link Layer Discovery Protocol (LLDP) messages of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a crash on an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient validation of LLDP messages in the PROFINET LLDP message handler. An attacker could exploit this vulnerability by sending a malicious LLDP message to an affected device. A successful exploit could allow the attacker to cause the affected device to reload.
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 exploit this vulnerability by sending a series of malicious DNS requests to an Umbrella Connector client interface of an affected device. A successful exploit could allow the attacker to cause a crash of the iosd process, which triggers a reload of the affected device.
Multiple vulnerabilities in the web management framework of Cisco IOS XE Software could allow an authenticated, remote attacker with read-only privileges to gain unauthorized read access to sensitive data or cause the web management software to hang or crash, resulting in a denial of service (DoS) condition. For more information about these vulnerabilities, see the Details section of this advisory.
Multiple vulnerabilities in the web management framework of Cisco IOS XE Software could allow an authenticated, remote attacker with read-only privileges to gain unauthorized read access to sensitive data or cause the web management software to hang or crash, resulting in a denial of service (DoS) condition. For more information about these vulnerabilities, see the Details section of this advisory.
A vulnerability in the WLAN Local Profiling feature of Cisco IOS XE Wireless Controller Software for the Cisco Catalyst 9000 Family could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to incorrect parsing of HTTP packets while performing HTTP-based endpoint device classifications. An attacker could exploit this vulnerability by sending a crafted HTTP packet to an affected device. A successful exploit could cause an affected device to reboot, resulting in a DoS condition.
Multiple vulnerabilities in the web management framework of Cisco IOS XE Software could allow an authenticated, remote attacker with read-only privileges to elevate privileges to the level of an Administrator user on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.
A vulnerability in the Split DNS feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability occurs because the regular expression (regex) engine that is used with the Split DNS feature of affected releases may time out when it processes the DNS name list configuration. An attacker could exploit this vulnerability by trying to resolve an address or hostname that the affected device handles. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
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 accessing the device using RESTCONF or NETCONF-YANG. A successful exploit could allow an attacker to cause the device to reload, resulting in a denial of service (DoS) condition.
A vulnerability in the persistent Telnet/Secure Shell (SSH) CLI of Cisco IOS XE Software could allow an authenticated, local attacker to gain shell access on an affected device and execute commands on the underlying operating system (OS) with root privileges. The vulnerability is due to insufficient enforcement of the consent token in authorizing shell access. An attacker could exploit this vulnerability by authenticating to the persistent Telnet/SSH CLI on an affected device and requesting shell access. A successful exploit could allow the attacker to gain shell access on the affected device and execute commands on the underlying OS with root privileges.
Multiple vulnerabilities in the web management framework of Cisco IOS XE Software could allow an authenticated, remote attacker with read-only privileges to elevate privileges to the level of an Administrator user on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.
A vulnerability in the UDP processing functionality of Cisco IOS XE Software for Embedded Wireless Controllers on Catalyst 9100 Series Access Points could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to the improper processing of UDP datagrams. An attacker could exploit this vulnerability by sending malicious UDP datagrams to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
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 attacker to execute arbitrary commands on the underlying operating system with root privileges. To exploit this vulnerability, an attacker must have valid Administrator privileges on the affected device.
A vulnerability in the processing of malformed Common Industrial Protocol (CIP) packets that are sent to Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to unexpectedly reload, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient input validation during processing of CIP packets. An attacker could exploit this vulnerability by sending a malformed CIP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to unexpectedly reload, resulting in a DoS condition.
A vulnerability in the software image verification functionality of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches could allow an unauthenticated, physical attacker to execute unsigned code at system boot time. This vulnerability is due to an improper check in the code function that manages the verification of the digital signatures of system image files during the initial boot process. An attacker could exploit this vulnerability by loading unsigned software on an affected device. A successful exploit could allow the attacker to boot a malicious software image or execute unsigned code and bypass the image verification check part of the boot process of the affected device. To exploit this vulnerability, the attacker needs either unauthenticated physical access to the device or privileged access to the root shell on the device. Note: In Cisco IOS XE Software releases 16.11.1 and later, root shell access is protected by the Consent Token mechanism. However, an attacker with level-15 privileges could easily downgrade the Cisco IOS XE Software running on a device to a release where root shell access is more readily available.
A vulnerability in the password-recovery disable feature of Cisco IOS XE ROM Monitor (ROMMON) Software for Cisco Catalyst Switches could allow an unauthenticated, local attacker to recover the configuration or reset the enable password. This vulnerability is due to a problem with the file and boot variable permissions in ROMMON. An attacker could exploit this vulnerability by rebooting the switch into ROMMON and entering specific commands through the console. A successful exploit could allow the attacker to read any file or reset the enable password.
A vulnerability in the Meraki onboarding feature of Cisco IOS XE Software could allow an authenticated, local attacker to gain root level privileges on an affected device. This vulnerability is due to insufficient memory protection in the Meraki onboarding feature of an affected device. An attacker could exploit this vulnerability by modifying the Meraki registration parameters. A successful exploit could allow the attacker to elevate privileges to root.
A vulnerability in the web UI of Cisco IOS XE Software could allow an authenticated, remote attacker to perform a directory traversal and access resources that are outside the filesystem mountpoint of the web UI. This vulnerability is due to an insufficient security configuration. An attacker could exploit this vulnerability by sending a crafted request to the web UI. A successful exploit could allow the attacker to gain read access to files that are outside the filesystem mountpoint of the web UI. Note: These files are located on a restricted filesystem that is maintained for the web UI. There is no ability to write to any files on this filesystem.
A vulnerability in the Cisco IOx application hosting subsystem of Cisco IOS XE Software could allow an authenticated, local attacker to elevate privileges to root on an affected device. This vulnerability is due to insufficient restrictions on the hosted application. An attacker could exploit this vulnerability by logging in to and then escaping the Cisco IOx application container. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with root privileges.
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. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-JP-DOS-g5FfGm8y