CVE-2021-1435: Cisco IOS XE Software Web UI Command Injection Vulnerability

Severity: high (CVSS 7.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 8.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-03-24 · updated 2026-06-17
Weakness: CWE-22

Description

A vulnerability in the web UI of Cisco IOS XE Software could allow an authenticated, remote attacker to inject arbitrary commands that can be executed as the root user. This vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending a crafted request to the web UI of an affected device with arbitrary commands injected into a portion of the request. A successful exploit could allow the attacker to execute arbitrary commands as the root user.

Affected products

Cisco IOS XE: 16.9.1, 16.9.1a, 16.9.1b, 16.9.1c, 16.9.1d, 16.9.1s (+30)

References

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