# CVE-2023-20198 — Cisco IOS XE Software

**CISA KEV**

> As of 2025-10-21, CVE-2023-20198 is a CRITICAL-severity vulnerability in Cisco IOS XE Software, CVSS v3.1 10, EPSS 99.5% (99.9th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-10-16), with a US federal remediation deadline of 2023-10-20. Threadlinqs Intelligence links 3 tracked threat campaigns to CVE-2023-20198, most recently “StrikeShark Campaign: SharkLoader Dropper Targets Governments and Software Developers via N-Day Exploits and Trojanized Installers to Deploy Cobalt Strike”.

**Last updated:** 2025-10-21

## What is CVE-2023-20198?

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.

The record classifies CVE-2023-20198 under weakness class [CWE-420](https://cwe.mitre.org/data/definitions/420.html). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 1063 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 10 — CRITICAL (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **EPSS (FIRST):** 99.5% probability of exploitation in the next 30 days, higher than 99.9% of all scored CVEs
- **CISA KEV:** Listed since 2023-10-16, federal remediation deadline 2023-10-20
- **Threadlinqs priority:** 9/10 — CISA KEV-listed, which Threadlinqs floors at 9
- **Published:** 2023-10-16, last modified 2025-10-21

## Is CVE-2023-20198 being exploited?

CISA added CVE-2023-20198 to the Known Exploited Vulnerabilities catalog on 2023-10-16, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2023-10-20 under BOD 22-01. Weaponised exploit code for CVE-2023-20198 is publicly available. 11 public proof-of-concept repositories are tracked for this identifier. A ProjectDiscovery Nuclei detection template exists (`http/cves/2023/CVE-2023-20198.yaml`). It currently carries a trending score of 45 in the Threadlinqs vulnerability feed.

- [smokeintheshell/CVE-2023-20198](https://github.com/smokeintheshell/CVE-2023-20198) (github)
- [W01fh4cker/CVE-2023-20198-RCE](https://github.com/W01fh4cker/CVE-2023-20198-RCE) (github)
- [fox-it/cisco-ios-xe-implant-detection](https://github.com/fox-it/cisco-ios-xe-implant-detection) (github)
- [ZephrFish/CVE-2023-20198-Checker](https://github.com/ZephrFish/CVE-2023-20198-Checker) (github)
- [Shadow0ps/CVE-2023-20198-Scanner](https://github.com/Shadow0ps/CVE-2023-20198-Scanner) (github)
- [Atea-Redteam/CVE-2023-20198](https://github.com/Atea-Redteam/CVE-2023-20198) (github)
- [Tounsi007/CVE-2023-20198](https://github.com/Tounsi007/CVE-2023-20198) (github)
- [Pushkarup/CVE-2023-20198](https://github.com/Pushkarup/CVE-2023-20198) (github)

## Affected products and versions

- **Cisco**: IOS XE Software

## How to fix CVE-2023-20198

Vendor advisory: [https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-webui-privesc-j22SaA4z](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-webui-privesc-j22SaA4z). Because CVE-2023-20198 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2023-10-20. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

## Threat activity tracking CVE-2023-20198

3 tracked threats in the Threadlinqs corpus reference CVE-2023-20198, either in the campaign’s CVE list or as an indicator on the campaign record.

- [StrikeShark Campaign: SharkLoader Dropper Targets Governments and Software Developers via N-Day Exploits and Trojanized Installers to Deploy Cobalt Strike](https://intel.threadlinqs.com/threat/TL-2026-1237) — HIGH · 2026-07-11
- [SharkLoader Malware Campaign Uses Fake Cisco AnyConnect and Google Update Installers to Deploy Cobalt Strike](https://intel.threadlinqs.com/threat/TL-2026-1101) — HIGH · 2026-07-03
- [SharkLoader Malware Deploys Cobalt Strike Beacon via DLL Side-Loading in StrikeShark Campaign](https://intel.threadlinqs.com/threat/TL-2026-0961) — HIGH · 2026-06-27

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, CISA KEV, GitHub Security Advisories, public proof-of-concept repositories, ProjectDiscovery Nuclei. Last verified by Threadlinqs on 2026-07-13. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [sec.cloudapps.cisco.com](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-webui-privesc-j22SaA4z)

Canonical: https://intel.threadlinqs.com/cve/CVE-2023-20198
Full detection coverage and IOCs for threats exploiting CVE-2023-20198 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp