Cisco IOS XE contains a command injection vulnerability in the web user interface. When chained with CVE-2023-20198, the attacker can leverage the new local user to elevate privilege to root and write the implant to the file system. Cisco identified CVE-2023-20273 as the vulnerability exploited to deploy the implant. CVE-2021-1435, previously associated with the exploitation events, is no longer believed to be related to this activity.
Cisco ยท Cisco IOS XE Web UI
Known ransomware use: Unknown
Follow the source advisory and validate exposure in your environment.
Verify that instances of Cisco IOS XE Web UI are in compliance with BOD 23-02 and apply mitigations per vendor instructions. For affected products (Cisco IOS XE Web UI exposed to the internet or to untrusted networks), follow vendor instructions to determine if a system may have been compromised and immediately report positive findings to CISA.
Recent reporting that mentions CVE-2023-20273.
Cisco has addressed the two vulnerabilities (CVE-2023-20198 and CVE-2023-20273) that hackers exploited to compromise tens of thousands of IOS XE devices over the past week. [...]
Cisco disclosed a new high-severity zero-day (CVE-2023-20273) today, actively exploited to deploy malicious implants on IOS XE devices compromised using the CVE-2023-20198 zero-day unveiled earlier this week. [...]