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 web-based management interface of Cisco Expressway Series could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the interface. This vulnerability exists because the web-based management interface does not properly validate user-supplied input. An attacker could exploit this vulnerability by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information. Note: Cisco Expressway Series refers to Cisco Expressway Control (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices.

A vulnerability in the REST API of Cisco Expressway Series and Cisco TelePresence VCS could allow an unauthenticated, remote attacker to conduct a cross-site request forgery (CSRF) attack on an affected system. This vulnerability is due to insufficient CSRF protections for the web-based management interface of an affected system. An attacker could exploit this vulnerability by persuading a user of the REST API to follow a crafted link. A successful exploit could allow the attacker to cause the affected system to reload. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. 

A vulnerability in the certificate validation of Cisco Expressway-C and Cisco TelePresence VCS could allow an unauthenticated, remote attacker to gain unauthorized access to sensitive data.  The vulnerability is due to a lack of validation of the SSL server certificate that an affected device receives when it establishes a connection to a Cisco Unified Communications Manager device. An attacker could exploit this vulnerability by using a man-in-the-middle technique to intercept the traffic between the devices, and then using a self-signed certificate to impersonate the endpoint. A successful exploit could allow the attacker to view the intercepted traffic in clear text or alter the contents of the traffic. Note: Cisco Expressway-E is not affected by this vulnerability.Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

A vulnerability in the restricted shell of Cisco Expressway Series could allow an authenticated, local attacker to perform command injection attacks on the underlying operating system and elevate privileges to root. To exploit this vulnerability, the attacker must have Administrator-level credentials with read-write privileges on an affected device. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by submitting a series of crafted CLI commands. A successful exploit could allow the attacker to escape the restricted shell and gain root privileges on the underlying operating system of the affected device. Note: Cisco Expressway Series refers to Cisco Expressway Control (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices.

A vulnerability in Cisco Expressway Edge (Expressway-E) could allow an authenticated, remote attacker to masquerade as another user on an affected system. This vulnerability is due to inadequate authorization checks for Mobile and Remote Access (MRA) users. An attacker could exploit this vulnerability by running a series of crafted commands. A successful exploit could allow the attacker to intercept calls that are destined for a particular phone number or to make phone calls and have that phone number appear on the caller ID. To successfully exploit this vulnerability, the attacker must be an MRA user on an affected system.

A vulnerability in the web-based management interface of Cisco Expressway Series could allow an unauthenticated, remote attacker to redirect a user to a malicious web page. This vulnerability is due to improper input validation of HTTP request parameters. An attacker could exploit this vulnerability by intercepting and modifying an HTTP request from a user. A successful exploit could allow the attacker to redirect the user to a malicious web page. Note: Cisco Expressway Series refers to Cisco Expressway Control (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices.

A vulnerability in the web-based management interface of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an authenticated, remote attacker with read-write privileges on the application to perform a command injection attack that could result in remote code execution on an affected device. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by sending a crafted request to the web-based management interface of an affected device. A successful exploit could allow the attacker to establish a remote shell with root privileges.

A vulnerability in the change password functionality of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an authenticated, remote attacker with Read-only credentials to elevate privileges to Administrator on an affected system. This vulnerability is due to incorrect handling of password change requests. An attacker could exploit this vulnerability by authenticating to the application as a Read-only user and sending a crafted request to the web-based management interface. A successful exploit could allow the attacker to alter the passwords of any user on the system, including an administrative user, and then impersonate that user. Note: Cisco Expressway Series refers to the Expressway Control (Expressway-C) device and the Expressway Edge (Expressway-E) device.

Multiple vulnerabilities in Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an authenticated attacker with Administrator-level read-only credentials to elevate their privileges to Administrator with read-write credentials on an affected system. Note: "Cisco Expressway Series" refers to Cisco Expressway Control (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices. For more information about these vulnerabilities, see the Details section of this advisory.