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 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.