A vulnerability in the web UI feature of Cisco IOS XE Software could allow an authenticated, remote attacker to inject commands with the privileges of root. This vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending crafted input to the web UI. A successful exploit could allow the attacker to inject commands to the underlying operating system with root privileges.

Cisco is providing an update for the ongoing investigation into observed exploitation of the web UI feature in Cisco IOS XE Software. We are updating the list of fixed releases and adding the Software Checker. Our investigation has determined that the actors exploited two previously unknown issues. The attacker first exploited CVE-2023-20198 to gain initial access and issued a privilege 15 command to create a local user and password combination. This allowed the user to log in with normal user access. The attacker then exploited another component of the web UI feature, leveraging the new local user to elevate privilege to root and write the implant to the file system. Cisco has assigned CVE-2023-20273 to this issue. CVE-2023-20198 has been assigned a CVSS Score of 10.0. CVE-2023-20273 has been assigned a CVSS Score of 7.2. Both of these CVEs are being tracked by CSCwh87343.

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

A vulnerability in the on-device application development workflow feature for the Cisco IOx application hosting infrastructure in Cisco IOS XE Software could allow an authenticated, remote attacker to access the underlying operating system as the root user. This vulnerability exists because Docker containers with the privileged runtime option are not blocked when they are in application development mode. An attacker could exploit this vulnerability by using the Docker CLI to access an affected device. The application development workflow is meant to be used only on development systems and not in production systems.

A vulnerability in the web UI 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. A successful exploit could allow the attacker to execute arbitrary Cisco IOS XE Software CLI commands with level 15 privileges. Note: This vulnerability is exploitable only if the attacker obtains the credentials for a Lobby Ambassador account. This account is not configured by default.

A vulnerability in the Layer 2 Tunneling Protocol (L2TP) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of certain L2TP packets. An attacker could exploit this vulnerability by sending crafted L2TP packets to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition. Note: Only traffic directed to the affected system can be used to exploit this vulnerability.

A vulnerability in the Multicast Leaf Recycle Elimination (mLRE) feature of Cisco IOS XE Software for Cisco ASR 1000 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to incorrect handling of certain IPv6 multicast packets when they are fanned out more than seven times on an affected device. An attacker could exploit this vulnerability by sending a specific IPv6 multicast or IPv6 multicast VPN (MVPNv6) packet through the affected device. A successful exploit could allow the attacker to cause a reload of the affected device, resulting in a DoS condition.

A vulnerability in the Authentication, Authorization, and Accounting (AAA) feature of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to bypass command authorization and copy files to or from the file system of an affected device using the Secure Copy Protocol (SCP). This vulnerability is due to incorrect processing of SCP commands in AAA command authorization checks. An attacker with valid credentials and level 15 privileges could exploit this vulnerability by using SCP to connect to an affected device from an external machine. A successful exploit could allow the attacker to obtain or change the configuration of the affected device and put files on or retrieve files from the affected device.

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.

A vulnerability in Cisco IOS XE Software for Cisco Catalyst 3650 and Catalyst 3850 Series Switches 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 improper resource management when processing traffic that is received on the management interface. An attacker could exploit this vulnerability by sending a high rate of traffic to the management interface. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

A vulnerability in Cisco IOS XE Software for Cisco Catalyst 9300 Series Switches could allow an authenticated, local attacker with level-15 privileges 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 errors that occur when retrieving the public release key that is used for image signature verification. An attacker could exploit this vulnerability by modifying specific variables in the Serial Peripheral Interface (SPI) flash memory of an affected device. A successful exploit could allow the attacker to execute persistent code on the underlying operating system. Note: In Cisco IOS XE Software releases 16.11.1 and later, the complexity of an attack using this vulnerability is high. However, an attacker with level-15 privileges could easily downgrade the Cisco IOS XE Software on a device to a release that would lower the attack complexity.

A vulnerability in the HTTP-based client profiling feature of Cisco IOS XE Software for Wireless LAN Controllers (WLCs) could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient input validation of received traffic. An attacker could exploit this vulnerability by sending crafted traffic through a wireless access point. A successful exploit could allow the attacker to cause CPU utilization to increase, which could result in a DoS condition on an affected device and could cause new wireless client associations to fail. Once the offending traffic stops, the affected system will return to an operational state and new client associations will succeed.

A vulnerability in the implementation of the IPv4 Virtual Fragmentation Reassembly (VFR) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper reassembly of large packets that occurs when VFR is enabled on either a tunnel interface or on a physical interface that is configured with a maximum transmission unit (MTU) greater than 4,615 bytes. An attacker could exploit this vulnerability by sending fragmented packets through a VFR-enabled interface on 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 Cisco IOx application hosting environment could allow an authenticated, remote attacker to execute arbitrary commands as root on the underlying host operating system. This vulnerability is due to incomplete sanitization of parameters that are passed in for activation of an application. An attacker could exploit this vulnerability by deploying and activating an application in the Cisco IOx application hosting environment with a crafted activation payload file. A successful exploit could allow the attacker to execute arbitrary commands as root on the underlying host operating system.

A vulnerability in the CLI of Cisco IOS XE SD-WAN Software could allow an authenticated, local attacker to execute arbitrary commands with root privileges. The vulnerability is due to insufficient input validation by the system CLI. An attacker could exploit this vulnerability by authenticating to an affected device and submitting crafted input to the system CLI. A successful exploit could allow the attacker to execute commands on the underlying operating system with root privileges.

A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE Software for Cisco Catalyst 9000 Family Wireless Controllers could allow an unauthenticated, remote attacker to execute arbitrary code with administrative privileges or cause a denial of service (DoS) condition on an affected device. The vulnerability is due to a logic error that occurs during the validation of CAPWAP packets. An attacker could exploit this vulnerability by sending a crafted CAPWAP packet to an affected device. A successful exploit could allow the attacker to execute arbitrary code with administrative privileges or cause the affected device to crash and reload, resulting in a DoS condition.

A vulnerability in IPv6 traffic processing of Cisco IOS XE Wireless Controller Software for Cisco Catalyst 9000 Family Wireless Controllers could allow an unauthenticated, adjacent attacker to cause a Layer 2 (L2) loop in a configured VLAN, resulting in a denial of service (DoS) condition for that VLAN. The vulnerability is due to a logic error when processing specific link-local IPv6 traffic. An attacker could exploit this vulnerability by sending a crafted IPv6 packet that would flow inbound through the wired interface of an affected device. A successful exploit could allow the attacker to cause traffic drops in the affected VLAN, thus triggering the DoS condition.

A vulnerability in the CLI of Cisco IOS XE SD-WAN Software and Cisco IOS XE Software could allow an authenticated, local attacker to execute arbitrary commands with elevated privileges on an affected device. This vulnerability is due to insufficient validation of arguments passed to certain CLI commands. An attacker could exploit this vulnerability by including malicious input in the argument of an affected command. A successful exploit could allow the attacker to execute arbitrary commands with elevated privileges on the underlying operating system. An attacker would need valid user credentials to exploit this vulnerability.

A vulnerability in the Voice Telephony Service Provider (VTSP) service of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass configured destination patterns and dial arbitrary numbers. This vulnerability is due to insufficient validation of dial strings at Foreign Exchange Office (FXO) interfaces. An attacker could exploit this vulnerability by sending a malformed dial string to an affected device via either the ISDN protocol or SIP. A successful exploit could allow the attacker to conduct toll fraud, resulting in unexpected financial impact to affected customers.

A vulnerability in the access control list (ACL) programming of Cisco ASR 900 and ASR 920 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to bypass a configured ACL. This vulnerability is due to incorrect programming of hardware when an ACL is configured using a method other than the configuration CLI. 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.