Known exploited vulnerability

CVE-2023-20273

Cisco IOS XE Web UI Command Injection Vulnerability

What is affected

Vendor Cisco
Product Cisco IOS XE Web UI
Weakness CWE-78

The vulnerability

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.

Required action

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 civilian agencies were required to act by 27 October 2023 under BOD 22-01. The deadline is a compliance date, not a measure of severity — it says nothing about how dangerous the flaw is to anyone else.

Where this comes from

Every field on this page is taken from the CISA Known Exploited Vulnerabilities catalog, last synced 13 Nov 2026, 00:30. Nothing here is our own assessment. For the technical scoring, see the NVD record below.

NVD record ↗ CVE.org record ↗

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