CVE-2023-20198: Cisco IOS XE Web UI Privilege Escalation Vulnerability

Critical severity, CVSS 10.0. Actively exploited: in CISA KEV since 2023-10-16. EPSS: 99.6% chance of exploitation in the next 30 days.

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.

Affected products

• Cisco IOS XE: from 16.12, before 16.12.10a (fixed in 16.12.10a); from 17.3, before 17.3.8a (fixed in 17.3.8a); from 17.6, before 17.6.6a (fixed in 17.6.6a); from 17.9, before 17.9.4a (fixed in 17.9.4a)
• Rockwellautomation Allen-Bradley Stratix 5200 Firmware: before 17.12.02 (fixed in 17.12.02)
• Rockwellautomation Allen-Bradley Stratix 5800 Firmware: before 17.12.02 (fixed in 17.12.02)

Published 2023-10-16. Last modified 2026-06-17.