{"id":"CVE-2021-34761","aliases":["EUVD-2021-21411","GHSA-3vcw-92x2-jjg4"],"status":"published","title":"Cisco Firepower Threat Defense Software CLI Arbitrary File Write Vulnerability","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.","severity":{"version":"3.1","score":4.4,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00216,"percentile":0.12098,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-20","CWE-668","CWE-73"],"published":"2021-10-27T18:55:30Z","modified":"2026-08-11T21:31:47Z","products":[{"vendor":"cisco","product":"cisco firepower threat defense software"},{"vendor":"cisco","product":"firepower_management_center_virtual_appliance"},{"vendor":"cisco","product":"secure_firewall_threat_defense"},{"vendor":"cisco","product":"sourcefire_defense_center"}],"references":[{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-file-write-SHVcmQVc","tags":["vendor-advisory","x_refsource_CISCO","x_transferred","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-34761"},{"url":"https://github.com/advisories/GHSA-3vcw-92x2-jjg4"}],"sources":{"cve":[{"id":"CVE-2021-34761","title":"Cisco Firepower Threat Defense Software CLI Arbitrary File Write Vulnerability","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.","status":"published","published":"2021-10-27T18:55:30.453Z","modified":"2024-11-07T21:44:29.552Z","cvss":[{"version":"3.1","score":4.4,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-73"],"updated_at":"2026-11-02T14:33:11.244759Z"}],"euvd":[{"id":"EUVD-2021-21411","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.","status":"published","published":"2021-10-27T18:55:30Z","modified":"2024-11-07T21:44:29Z","cvss":[{"version":"3.1","score":4.4,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N","level":"medium"}],"updated_at":"2026-11-03T00:05:07.826667Z"}],"ghsa":[{"id":"GHSA-3vcw-92x2-jjg4","title":"A vulnerability in Cisco Firepower Threat Defense (FTD) Software could allow an authenticated,...","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.","status":"published","published":"2022-05-24T19:18:55Z","modified":"2026-08-11T21:31:47Z","cvss":[{"version":"3.1","score":6,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H","level":"medium"}],"cwes":["CWE-20","CWE-73","CWE-668"],"updated_at":"2026-11-02T15:10:21.509652Z"}],"nvd":[{"id":"CVE-2021-34761","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.","status":"published","published":"2021-10-27T19:15:08.003Z","modified":"2026-08-11T19:33:44.513Z","cvss":[{"version":"3.1","score":4.4,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":6,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H","level":"medium","assessor":"primary"},{"version":"2.0","score":6.6,"vector":"AV:L/AC:L/Au:N/C:N/I:C/A:C","level":"medium","assessor":"primary"}],"cwes":["CWE-73","CWE-668"],"updated_at":"2026-11-02T14:07:00.549994Z"}]}}