CVE-2023-20273: Cisco IOS XE Web UI Command Injection Vulnerability
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
Cisco IOS XE contains a command injection vulnerability in the web user interface. When chained with CVE-2023-20198, the attacker can leverage the new local user to elevate privilege to root and write the implant to the file system. Cisco identified CVE-2023-20273 as the vulnerability exploited to deploy the implant. CVE-2021-1435, previously associated with the exploitation events, is no longer believed to be related to this activity.
CSIRTS triage
- What
- Cisco IOS XE contains a command injection vulnerability in the web user interface.
- Who is affected
- Deployments of Cisco IOS XE with the web UI enabled.
- Urgency
- Remediation is urgent as the vulnerability is actively exploited and is critical in severity.
- Action
- Apply the latest security updates to address this vulnerability.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2023-20273
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Exploitation confirmedCVE-2023-20273Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 100% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2023-20273 | coverage & exploitation status | NVD · CVE.org |
Recent advisories for Cisco IOS XE
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- mediumCisco IOS XE Software Denial of Service Vulnerabilitycisco-psirt · 2026-04-02
- criticalexploitedCVE-2025-20352: Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution Vulnerabilitycisa-kev · 2025-09-29
- unknownexploited[Update] Multiple vulnerabilities in Cisco IOS XE (October 17, 2023)cert-fr-alerte · 2023-10-17
- criticalexploitedCVE-2023-20198: Cisco IOS XE Web UI Privilege Escalation Vulnerabilitycisa-kev · 2023-10-16
- criticalexploitedCVE-2023-20109: Cisco IOS and IOS XE Group Encrypted Transport VPN Out-of-Bounds Write Vulnerabilitycisa-kev · 2023-10-10
- criticalexploitedCVE-2016-6415: Cisco IOS, IOS XR, and IOS XE IKEv1 Information Disclosure Vulnerabilitycisa-kev · 2023-05-19
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