{"cve":"CVE-2021-40120","nvd":{"published":"2021-11-04T16:15:09.430","modified":"2026-06-17T04:06:33.550","status":"Modified","description":"A vulnerability in the web-based management interface of certain Cisco Small Business RV Series Routers could allow an authenticated, remote attacker with administrative privileges to inject arbitrary commands into the underlying operating system and execute them using root-level privileges. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by sending malicious input to a specific field in the web-based management interface of an affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying Linux operating system as a user with root-level privileges.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","score":7.2},"cwes":["CWE-78","CWE-20"],"references":["https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sbrv-cmdinjection-Z5cWFdK","https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sbrv-cmdinjection-Z5cWFdK"],"products":["cisco:application_extension_platform","cisco:ios_xr"],"source":"nvd","synced_at":"2026-10-19T21:24:39.218183596+00:00"},"epss":{"cve":"CVE-2021-40120","score":0.01999,"percentile":0.80741,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}