medium
6.9
CWE
347
Advisory Published
Updated

CVE-2019-1736: Multiple Cisco UCS-Based Products UEFI Secure Boot Bypass Vulnerability

First published: Wed Sep 23 2020(Updated: )

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.

Credit: ykramarz@cisco.com

Affected SoftwareAffected VersionHow to fix
All of
Cisco FMC 1000-K9<4.0.1f.0
Cisco FMC 1000-K9<4.0.2h
All of
Cisco FMC 2500-K9<4.0.1f.0
Cisco Firepower Management Center 2500 firmware<4.0.2h
All of
Cisco FMC 4500-K9<4.0.1f.0
Cisco Firepower Management Center 4500<4.0.2h
All of
Cisco SNS-3515-K9 BIOS<4.0.2d
Cisco sns-3515-k9 firmware<4.0.2h
All of
Cisco SNS-3595-K9<4.0.2d
Cisco SNS-3595-K9<4.0.2h
All of
Cisco SNS-3615-K9<4.0.1i
Cisco SNS-3615-K9<4.0.1g
All of
Cisco SNS-3655-K9 BIOS<4.0.1i
Cisco SNS-3655-K9 Firmware<4.0.1g
All of
Cisco sns-3695-k9 bios<4.0.1i
Cisco SNS-3695-K9 Firmware<4.0.1g
All of
Cisco TG5004-K9-RF BIOS<4.0.2d
Cisco tg5004-k9-rf firmware<4.0.2h
All of
Cisco TG5004-K9-RF BIOS<4.0.2d
Cisco tg5004-k9 firmware<4.0.2h
Cisco Identity Services Engine=2.4\(0.357\)
Cisco Identity Services Engine=2.6\(0.156\)
Cisco Unified Computing System software=3.2\(3h\)c

Remedy

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200219-ucs-boot-bypass

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Reference Links

Frequently Asked Questions

  • What is CVE-2019-1736?

    CVE-2019-1736 is a vulnerability in the firmware of the Cisco UCS C-Series Rack Servers that allows an authenticated, physical attacker to bypass UEFI Secure Boot validation checks and load a compromised software image on an affected device.

  • How can an attacker exploit CVE-2019-1736?

    An attacker can exploit CVE-2019-1736 by physically accessing the Cisco UCS C-Series Rack Server and bypassing the UEFI Secure Boot validation checks.

  • What is the severity of CVE-2019-1736?

    The severity of CVE-2019-1736 is medium, with a CVSS score of 6.6.

  • Which Cisco products are affected by CVE-2019-1736?

    Cisco UCS C-Series Rack Servers, Cisco Identity Services Engine, and Cisco Unified Computing System are affected by CVE-2019-1736.

  • How can I fix CVE-2019-1736?

    To fix CVE-2019-1736, Cisco recommends upgrading to the appropriate fixed version of the firmware or software.

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