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

- Exploited (CISA KEV): yes, added 2023-10-16
- Published: 2023-10-16
- CVSS: 10 CRITICAL (v3.1)
- EPSS: 99.6% (100th percentile)
- CWE: CWE-420

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.

## Edge WAF coverage (claimed by vendors, not measured)

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Blocks by default | 2025-03-10 | 511 |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | Before feed history | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2023-12-12 | 57 |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### Cloudflare

- 2025-03-10 · new · rule fda130e396224ffc9f0a9e72259073d5 · default Block
  > Cisco IOS XE - Information Disclosure - CVE:CVE-2023-20198. Previous action: Log. New action: Block. This is a New Detection
  Source: https://developers.cloudflare.com/changelog/post/2025-03-10-waf-release/
- 2025-03-17 · updated · rule 19ae0094a8d845a1bb1997af0ad61fa7 · default Disabled
  > Cisco IOS XE - Remote Code Execution - CVE:CVE-2023-20198. Previous action: Log. New action: Disabled. Fixed action value in changelog; no rule changes.
  Source: https://developers.cloudflare.com/changelog/post/2025-03-17-waf-release/

### F5

- 2023-12-12 · new · rule 200013068
  > Added: signature 200013068 "Cisco IOS XE Authorization Bypass" (Authentication/Authorization Attacks, risk High), systems: Cisco. References: CVE-2023-20198.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog

## Our test (measured)

- OWASP Core Rule Set 4.25.0, paranoia level 1, anomaly threshold 5, default CRS settings: blocked (3 of 3 requests blocked), template CVE-2023-20198, 2026-11-02
- OWASP Core Rule Set 4.25.0, paranoia level 2, anomaly threshold 5, default CRS settings: blocked (3 of 3 requests blocked), template CVE-2023-20198, 2026-11-02

"No public claim" means no vendor statement names this CVE; "Before feed history" means the CVE is older than the vendor feed. In both cases generic rules may still block it.

HTML: https://cve.vigilbase.com/cve/CVE-2023-20198 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2023-20198