Firmware flaws could allow a malicious reflash, US CERT warns

U.S. CERT warned of three issues that could affect critical firmware

Three vendors have released fixes for vulnerabilities found in the critical firmware used during a computer's startup, according to an advisory from the U.S. Computer Emergency Readiness Team.

The vulnerabilities could allow an attacker to bypass a feature called Secure Boot, which verifies that firmware components carry a correct digital signature ensuring the software's authenticity. The attacker could then replace the device's firmware.

The flaws lie within some UEFI (unified extensible firmware interface) systems, the advisory said. UEFI is a firmware interface that was designed to improve upon BIOS.

A boot script within the UEFI S3 Resume path "resides in unprotected memory which can be tampered with by an attacker with access to physical memory," the advisory said.

An authenticated local attacker could bypass Secure Boot and reflash, or replace, the firmware even if signed firmware updates are supposed to be used. An attack could also cause a system to be inoperable.

Several vendors have taken action. American Megatrends Incorporated (AMI), which makes BIOS and UEFI firmware, has "addressed the issue on a generic basis and is working with OEMs to implement fixes for projects in the field and production."

Intel and Phoenix Technologies, which also makes UEFI software, have issued fixes, the advisory said.

The advisory was one of three issued by U.S. CERT on Monday. The agency also warned of a "race condition" vulnerability in some Intel chipsets that could allow the bypass of a BIOS locking mechanism, allowing malicious code to be inserted into firmware.

American Megatrends and Phoenix Technologies have issued updates to address the issue, but it's unknown if other major vendors may be affected, according to the advisory.

U.S. CERT also warned in a third advisory of a buffer overflow in the open-source EDK1 project's UEFI reference implementation. One affected vendor that uses the firmware, Insyde Software, has fixed the issue.

American Megatrends, Apple, IBM, Intel and Phoenix Technologies are not affected by that flaw. However, it's not known whether other large vendors may be vulnerable.

Send news tips and comments to Follow me on Twitter: @jeremy_kirk

Join the CSO newsletter!

Error: Please check your email address.

Tags AppleIBMsecurityU.S. Computer Emergency Readiness TeamInsyde SoftwareExploits / vulnerabilitiesAmerican MegatrendsintelPhoenix Technologies

More about AppleIntelPhoenixPhoenix Technologies

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by Jeremy Kirk

Latest Videos

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

  • 150x50

    IDG Live Webinar:The right collaboration strategy will help your business take flight

    Speakers - Mike Harris, Engineering Services Manager, Jetstar - Christopher Johnson, IT Director APAC, 20th Century Fox - Brent Maxwell, Director of Information Systems, THE ICONIC - IDG MC/Moderator Anthony Caruana

    Play Video

More videos

Blog Posts