{"cve":"CVE-2021-34761","nvd":{"published":"2021-10-27T19:15:08.003","modified":"2026-08-11T19:33:44.513","status":"Modified","description":"A vulnerability in Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to overwrite or append arbitrary data to system files using root-level privileges. The attacker must have administrative credentials on the device. This vulnerability is due to incomplete validation of user input for a specific CLI command. An attacker could exploit this vulnerability by authenticating to the device with administrative privileges and issuing a CLI command with crafted user parameters. A successful exploit could allow the attacker to overwrite or append arbitrary data to system files using root-level privileges.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H","score":6.0},"cwes":["CWE-668","CWE-73"],"references":["https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-file-write-SHVcmQVc","https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-file-write-SHVcmQVc"],"products":["cisco:firepower_management_center_virtual_appliance","cisco:secure_firewall_threat_defense","cisco:sourcefire_defense_center"],"source":"nvd","synced_at":"2026-10-19T21:24:39.218183596+00:00"},"epss":{"cve":"CVE-2021-34761","score":0.00216,"percentile":0.12013,"date":"2026-11-01"},"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."]}