{"id":"CVE-2019-1736","aliases":["EUVD-2019-10293","GHSA-pwvv-633w-65j9"],"status":"published","title":"Multiple Cisco UCS-Based Products UEFI Secure Boot Bypass Vulnerability","description":"A vulnerability in the firmware of the Cisco UCS C-Series Rack Servers could allow an authenticated, physical attacker to bypass Unified Extensible Firmware Interface (UEFI) Secure Boot validation checks and load a compromised software image on an affected device. The vulnerability is due to improper validation of the server firmware upgrade images. An attacker could exploit this vulnerability by installing a server firmware version that would allow the attacker to disable UEFI Secure Boot. A successful exploit could allow the attacker to bypass the signature validation checks that are done by UEFI Secure Boot technology and load a compromised software image on the affected device. A compromised software image is any software image that has not been digitally signed by Cisco.","severity":{"version":"3.0","score":6.2,"vector":"CVSS:3.0/AV:P/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-08","score":0.00247,"percentile":0.1602,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-347"],"published":"2020-09-23T00:26:09Z","modified":"2026-06-17T02:29:09Z","products":[{"vendor":"cisco","product":"cisco identity services engine software"},{"vendor":"cisco","product":"fmc1000-k9_bios"},{"vendor":"cisco","product":"fmc1000-k9_firmware"},{"vendor":"cisco","product":"fmc2500-k9_bios"},{"vendor":"cisco","product":"fmc2500-k9_firmware"},{"vendor":"cisco","product":"fmc4500-k9_bios"},{"vendor":"cisco","product":"fmc4500-k9_firmware"},{"vendor":"cisco","product":"identity_services_engine"},{"vendor":"cisco","product":"sns-3515-k9_bios"},{"vendor":"cisco","product":"sns-3515-k9_firmware"},{"vendor":"cisco","product":"sns-3595-k9_bios"},{"vendor":"cisco","product":"sns-3595-k9_firmware"},{"vendor":"cisco","product":"sns-3615-k9_bios"},{"vendor":"cisco","product":"sns-3615-k9_firmware"},{"vendor":"cisco","product":"sns-3655-k9_bios"},{"vendor":"cisco","product":"sns-3655-k9_firmware"},{"vendor":"cisco","product":"sns-3695-k9_bios"},{"vendor":"cisco","product":"sns-3695-k9_firmware"},{"vendor":"cisco","product":"tg5004-k9-rf_bios"},{"vendor":"cisco","product":"tg5004-k9-rf_firmware"},{"vendor":"cisco","product":"tg5004-k9_bios"},{"vendor":"cisco","product":"tg5004-k9_firmware"},{"vendor":"cisco","product":"unified_computing_system"}],"references":[{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200219-ucs-boot-bypass","tags":["vendor-advisory","x_refsource_CISCO","x_transferred","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2019-1736"},{"url":"https://github.com/advisories/GHSA-pwvv-633w-65j9"}],"sources":{"cve":[{"id":"CVE-2019-1736","title":"Multiple Cisco UCS-Based Products UEFI Secure Boot Bypass Vulnerability","description":"A vulnerability in the firmware of the Cisco UCS C-Series Rack Servers could allow an authenticated, physical attacker to bypass Unified Extensible Firmware Interface (UEFI) Secure Boot validation checks and load a compromised software image on an affected device. The vulnerability is due to improper validation of the server firmware upgrade images. An attacker could exploit this vulnerability by installing a server firmware version that would allow the attacker to disable UEFI Secure Boot. A successful exploit could allow the attacker to bypass the signature validation checks that are done by UEFI Secure Boot technology and load a compromised software image on the affected device. A compromised software image is any software image that has not been digitally signed by Cisco.","status":"published","published":"2020-09-23T00:26:09.923Z","modified":"2024-11-13T18:05:16.337Z","cvss":[{"version":"3.0","score":6.2,"vector":"CVSS:3.0/AV:P/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T14:20:25.661187Z"}],"euvd":[{"id":"EUVD-2019-10293","description":"A vulnerability in the firmware of the Cisco UCS C-Series Rack Servers could allow an authenticated, physical attacker to bypass Unified Extensible Firmware Interface (UEFI) Secure Boot validation checks and load a compromised software image on an affected device. The vulnerability is due to improper validation of the server firmware upgrade images. An attacker could exploit this vulnerability by installing a server firmware version that would allow the attacker to disable UEFI Secure Boot. A successful exploit could allow the attacker to bypass the signature validation checks that are done by UEFI Secure Boot technology and load a compromised software image on the affected device. A compromised software image is any software image that has not been digitally signed by Cisco.","status":"published","published":"2020-09-23T00:26:09Z","modified":"2024-11-13T18:05:16Z","cvss":[{"version":"3.0","score":6.2,"vector":"CVSS:3.0/AV:P/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","level":"medium"}],"updated_at":"2026-11-03T00:05:01.673157Z"}],"ghsa":[{"id":"GHSA-pwvv-633w-65j9","title":"A vulnerability in the firmware of the Cisco UCS C-Series Rack Servers could allow an...","description":"A vulnerability in the firmware of the Cisco UCS C-Series Rack Servers could allow an authenticated, physical attacker to bypass Unified Extensible Firmware Interface (UEFI) Secure Boot validation checks and load a compromised software image on an affected device. The vulnerability is due to improper validation of the server firmware upgrade images. An attacker could exploit this vulnerability by installing a server firmware version that would allow the attacker to disable UEFI Secure Boot. A successful exploit could allow the attacker to bypass the signature validation checks that are done by UEFI Secure Boot technology and load a compromised software image on the affected device. A compromised software image is any software image that has not been digitally signed by Cisco.","status":"published","published":"2022-05-24T17:29:15Z","modified":"2023-01-29T05:04:08Z","cwes":["CWE-347"],"updated_at":"2026-11-02T14:45:28.958037Z"}],"nvd":[{"id":"CVE-2019-1736","description":"A vulnerability in the firmware of the Cisco UCS C-Series Rack Servers could allow an authenticated, physical attacker to bypass Unified Extensible Firmware Interface (UEFI) Secure Boot validation checks and load a compromised software image on an affected device. The vulnerability is due to improper validation of the server firmware upgrade images. An attacker could exploit this vulnerability by installing a server firmware version that would allow the attacker to disable UEFI Secure Boot. A successful exploit could allow the attacker to bypass the signature validation checks that are done by UEFI Secure Boot technology and load a compromised software image on the affected device. A compromised software image is any software image that has not been digitally signed by Cisco.","status":"published","published":"2020-09-23T01:15:14.3Z","modified":"2026-06-17T02:29:09.757Z","cvss":[{"version":"3.1","score":6.6,"vector":"CVSS:3.1/AV:P/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"medium","assessor":"primary"},{"version":"3.0","score":6.2,"vector":"CVSS:3.0/AV:P/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","level":"medium","assessor":"secondary"},{"version":"2.0","score":6.9,"vector":"AV:L/AC:M/Au:N/C:C/I:C/A:C","level":"medium","assessor":"primary"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T14:05:47.558959Z"}]}}