Cisco IOS XE Web UI Privilege Escalation Vulnerability
CVE-2023-20198 is a security vulnerability in Cisco IOS XE Web UI, added to CISA KEV on October 16, 2023. Patch priority: Patch this week.
What it is
Cisco IOS XE Web UI contains a privilege escalation vulnerability in the web user interface that could allow a remote, unauthenticated attacker to create an account with privilege level 15 access. The attacker can then use that account to gain control of the affected device.
Who's affected
Affects anyone with Cisco networking or security appliances on their network — typically a firewall, switch, or remote-access VPN. That device controls traffic to and from every workstation; exploitation can mean an attacker pivots inside the network without touching any user device.
What to do
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.
If you don't have someone in-house to verify the patch deployed across every endpoint — or you're not sure whether you're affected — that's exactly the kind of triage we do. Book a free 20-minute triage call.
Insurance readiness
Your insurer will ask if this is patched.
Unpatched entries on CISA's Known Exploited Vulnerabilities list are exactly what cyber-insurance carrier questionnaires probe for, and knowing which controls they check is how you keep a renewal from stalling.
Get the free carrier questionnaire →Severity
CVSS base score: 10.0 — CRITICAL
Weakness classification: CWE-420
CISA due date
Federal deadline: October 20, 2023. Federal agencies must complete the required action by this date. For private SMBs the deadline is advisory — but treat it as a strong recommendation, especially if you handle regulated data (HIPAA, GLBA, ABA model rules).
EPSS
EPSS score: 99.6% — higher than 100% of all scored CVEs.
EPSS estimates the probability of exploitation activity in the next 30 days. Every entry on this site is already confirmed exploited, so read it as relative urgency among the things you still have open, not as permission to wait.
Source
This entry comes from CISA's Known Exploited Vulnerabilities catalog, public US-Government data we pull daily. The plain-language framing and the what-to-do guidance above are ours. View the original entry on cisa.gov.