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

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

• Documented mitigation — sec.cloudapps.cisco.com (NIST National Vulnerability Database)

CISA required action CISA

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.

US federal deadline: Oct 20, 2023 — passed 1091 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

1. Identify exposed assets running the affected vendor/product/version combinations (Cisco Cisco IOS XE Software, Cisco Ios Xe, Rockwell Automation Allen-bradley Stratix 5200 Firmware…).
2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
3. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
4. Apply the documented mitigations until a definitive fix is available.
5. EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
6. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-420

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 99.57%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

• Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
• Hunt retroactively in logs from before Oct 16, 2023 (KEV listing): exploitation may have started earlier.

Timeline

What happened to this CVE, newest first.

• 2026
• Fix documented
  Oct 13, 2026 · NIST National Vulnerability Database
• Affected products added · rockwellautomation/allen-bradley stratix 5200 firmware, rockwellautomation/allen-bradley stratix 5800 firmware, cisco/io
  Oct 13, 2026 · NIST National Vulnerability Database
• Source status changed · Published → Analyzed
  Oct 13, 2026 · NIST National Vulnerability Database
• Record published
  Oct 13, 2026
• Affected products added · cisco/cisco ios xe software
  Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
• CVSS changed · 10.0
  Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
• Source status changed · → Published
  Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
• SSVC assessment updated
  Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
• Added to CISA KEV (detected)
  Oct 13, 2026 · CISA Known Exploited Vulnerabilities
• Record created in this database
  Oct 13, 2026 · CISA Known Exploited Vulnerabilities
• 2023
• CVE published
  Oct 16, 2023 · cisco
• Added to CISA KEV catalog
  Oct 15, 2023 · CISA

Source activity

Repeated readings are counted rather than listed.

• 3× References added · Oct 13, 2026 – Oct 13, 2026
• 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

8 on the record

• sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-webui-pr
  Mitigation, Vendor Advisory, CVE Program (cve.org) e CISA ADP
• www.cisa.gov/known-exploited-vulnerabilities-catalog
  US Government Resource, NIST National Vulnerability Database
• github.com/advisories/GHSA-4xrf-pcxr-rf3c
  GitHub Security Advisories
• www.darkreading.com/vulnerabilities-threats/critical-unpatched-cisco-zero-day-bug-active-
  GitHub Security Advisories
• arstechnica.com/security/2023/10/actively-exploited-cisco-0-day-with-maximum-10-sever
  GitHub Security Advisories
• nvd.nist.gov/vuln/detail/CVE-2023-20198
  GitHub Security Advisories
• www.cisa.gov/guidance-addressing-cisco-ios-xe-web-ui-vulnerabilities
  GitHub Security Advisories
• packetstormsecurity.com/files/175674/Cisco-IOX-XE-Unauthenticated-Remote-Code-Execution.html
  GitHub Security Advisories

Elsewhere on this site

Related CVEs (same products)

• Medium CVE-2026-20311 Cisco IOS XE Software Web UI Denial of Service Vulnerability Aug 5, 2026
• Medium CVE-2026-20308 Cisco IOS XE Software Web-Based Management Interface Vulnerability Aug 5, 2026
• High CVE-2026-20301 Cisco IOS Software and IOS XE Software Extensible Messaging Client Protocol Denial of Service Vulnerability Aug 5, 2026
• High CVE-2026-20273 Cisco IOS XE Software Security Hardening Release Aug 5, 2026
• Critical CVE-2026-20272 Cisco IOS XE Software Security Hardening Release Aug 5, 2026
• High CVE-2026-20269 Cisco IOS XE Software Security Hardening Release Aug 5, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

• No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
• No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
• No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2023-20198 is "Cisco IOS XE Web UI Privilege Escalation Vulnerability", rated Critical. It affects Cisco IOS XE Software (Cisco); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 10.0 describes technical severity. EPSS 99.57% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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