As a researcher, I am primarily interested in cyber security with a focus on the boundaries between hardware and software. This stems from my long-term exposure to assembly, binary exploitation, and reverse engineering — all of which I learned on my own and through Capture the Flag competitions and wargames.
My research interests began in 2014 as an undergraduate at the University of Central Florida. There I joined the Security in Silicon Lab (SSL), a hardware and software security lab. There I lead a security analysis of the brand new Google Nest thermostat, in which we discovered a way to gain root access. We disseminated these findings to Black Hat USA that same year. Propelled from the success of this work, my UCF advisor Dr. Yier Jin continued investigating other Internet of Things devices after I graduated.
For graduate school, I joined the University of Florida to pursue my Ph.D in August 2015. I found a new home in the newly formed Florida Institute of Cyber Security Research (FICS). There I found a new advisor, Dr. Kevin Butler and joined him as a Research Assistant. Over the last three years I have been exposed to his background on systems security and USB research and continue to develop my own direction. Currently, my focus lies on embedded firmware analysis and how to instrument exotic embedded platforms.
University of Florida, Research Assistant with FICS
Gainesville, FL – Fall 2015 - Present
- Advisor: Dr. Kevin R. B. Butler
- Area: Systems security
- Thesis: Developing methodologies for automatically analyzing embedded binary firmware.
- Performing large-scale analysis of Android firmware to explore hidden USB interfaces and device security policies
- Analyzing USB firmware using symbolic execution to automatically reason about device functionality
- Employed Intel SGX to balance Secure Function Evaluation (SFE) security with performance
- Worked to improve TLS security and agility through server-side enhancements
University of Central Florida, Undergraduate Research Assistant
Orlando, FL – Summer 2013 - 2014
- Advisor: Dr. Yier Jin
- Area: Internet of Things security
- Discovered a USB entry point into Google’s Nest Thermostat allowing full-root access
- Published findings at Black Hat USA 2014 entitled “Smart Nest Thermostat: A Smart Spy in your Home”
University of Central Florida, EXCEL Undergraduate Research
Orlando, FL – Spring 2013
- Advisor: Dr. Mingjie Lin
- Area: FPGAs
- Learned Verilog through working with a HDL Huffman decoder
Publications & Academic Work
- D. Tian, G. Hernandez, J. Choi, V. Frost, P. Johnson, and K. Butler. LBM: A Security Framework for Peripherals within the Linux Kernel. IEEE S&P, 2019.
- D. Tian, J. Choi, G. Hernandez, P. Traynor, and K. Butler. A Practical Intel SGX Setting for Linux Containers in the Cloud. ACM CODASPY, 2019.
- D. Tian, G. Hernandez, J. Choi, V. Frost, C. Ruales, K. Butler, P. Traynor, H. Vijayakumar, L. Harrison, A. Rahmati, and M. Grace. ATtention Spanned: Comprehensive Vulnerability Analysis of AT Commands Within the Android Ecosystem. USENIX Security, 2018.
- G. Hernandez, F. Fowze, D. Tian, T. Yavuz, and K. Butler. FirmUSB: Vetting USB Device Firmware using Domain Informed Symbolic Execution. ACM CCS, 2017.
- S. Etigowni, D. Tian, G. Hernandez, S. Zonouz, and K. Butler. CPAC: Securing Critical Infrastructure with Cyber-Physical Access Control. ACSAC, 2016.
- G. Hernandez, O. Arias, D. Buentello, and Y. Jin. Smart Nest Thermostat: A Smart Spy in your Home. Black Hat USA, 2014.
- A. Bates, D. Tian, G. Hernandez, T. Moyer, K. Butler, and T. Jaeger. Taming the Costs of Trustworthy Provenance through Policy. Transactions on Internet Technology (TOIT), 2016.
- G. Hernandez, K. Butler. Android Escalation Paths: Building Attack-Graphs from SEAndroid Policies. ACM Security & Privacy in Wireless and Mobile Networks (WiSec), 2018
- G. Hernandez, D. Tian, J. Choi, V. Frost, C. Ruales, K. Butler, P. Traynor, H. Vijayakumar, L. Harrison, A. Rahmati, and M. Grace. ATtention Spanned: Comprehensive Vulnerability Analysis of AT Commands Within the Android Ecosystem. SEC Academic Conference, Apr. 2018. (Best Poster)
- — . ATtention Spanned: Comprehensive Vulnerability Analysis of AT Commands Within the Android Ecosystem. FICS Conference, Mar. 2018.
- G. Hernandez, F. Fowze, D. Tian, C. Metcalf, T. Yavuz, and K. Butler. FirmUSB: Vetting USB Device Firmware using Domain Informed Symbolic Execution. FICS Conference, Mar. 2017. (Best Poster)
- G. Hernandez, A. Bates, and K. Butler. SSL Certificate Verification Enhancements for the Server. FICS Conference, 2016
- G. Hernandez and Y. Jin. Smart Nest Thermostat: A Smart Spy in your Home. UCF Showcase for Undergraduate Research, 2015
- S. Deshmukh, H. Carter, G. Hernandez, P. Traynor, and K. Butler. Efficient and Secure Template Blinding for Biometric Authentication. Proceedings of the IEEE Workshop on Security and Privacy in the Cloud (SPC), 2016.
Program Chair Assistant
- Network & Distributed System Security Symposium (NDSS) – 2017
Assisted Ari Juels with recording HotCRP accept/reject decisions, limiting paper discussion time, and synchronizing dual-track PC meeting via custom spreadsheet.
- IEEE Symposium on Security & Privacy (Oakland, S&P) - 2017
- USENIX Security Symposium (USENIX Security) – 2017, 2018
- ACM Conference on Computer and Communications Security (CCS) - 2016, 2017
- ACM Asia Conference on Computer and Communications Security (AsiaCCS) - 2017, 2018
- Annual Computer Security Applications Conference (ACSAC) – 2017
- Network & Distributed System Security Symposium (NDSS) - 2017, 2018
- USENIX Symposium on Operating Systems Design and Implementation (OSDI) - 2016
- USENIX Workshop on Offensive Technologies Workshop on Offensive Technologies (WOOT) - 2016, 2017
- System Administrator for the Florida Institute of Cyber Security (FICS). Responsible for user management, patching, hardening, and monitoring 9 business-critical servers. (2015 – present)
- Helped develop, organize and run SwampCTF, a 48 hour international Capture the Flag competition, for the Student InfoSec Team (UFSIT). Built infrastructure using Ansible, Docker, AWS, and Netdata. Over 1,200 registered teams enjoyed our 28 hand-crafted cyber security challenges (March 2018).
- Advising and training the University of Florida’s Collegiate Cyber Defense Team (UFCCDC) under UF’s Registered Student Organization (RSO) the Student InfoSec Team (UFSIT) (2016-2017). Reference: Dr. Joseph Wilson (firstname.lastname@example.org)
Honors & Awards
- Best poster: “ATtention Spanned: Comprehensive Vulnerability Analysis of AT Commands Within the Android Ecosystem.” (SEC Academic Conference, Apr. 2018)
- CISE Graduate Scholarship (2017)
- 3rd place at the Southeast Regional Collegiate Cyber Defense Competition (SECCDC) (2017)
- Best poster: “FirmUSB: Vetting USB Device Firmware using Domain Informed Symbolic Execution.” (FICS Conference, Mar. 2017)
- Harris Communication Fellowship (2015)
- Appointed as Florida Institute of National Security (FINS) Fellow (2015)
- Graduate School Fellowship Award (2015 - 2019)
University of Central Florida
- ICubed (I3) Fellow - presented Nest security research to an Advanced Painting class, inspiring their work (2015)
- Winner of the National Collegiate Cyber Defense Competition (NCCDC) out of 180 schools (April 2014)
- 1st place at the Southeast Regional Collegiate Cyber Defense Competition (SECCDC) (2013 and 2014)
- 2nd place at the UCONN CyberSEED Buffer Overflow competition (2014)
- 6th place and 5th place at CSAW CTF finals (2013 and 2014 respectively)
- UCF President’s Honor Role, 4.0 GPA (Fall 2011, Spring 2012, Fall 2012)
- EXCEL Student - NSF STEM only education program with guaranteed Sophomore year research (2011 - 2013)
- 1st place at UCF’s 25th annual High School Programming Tournament
- A Journey into Fuzzing with American Fuzzy Lop. Hack@UCF (2015)
- Smart Nest Thermostat: Smart Spy in your Home. Black Hat USA (2015)
- “Smartphone security risk compared to ‘having a ghost user on your phone’ ”
– University of Florida News (Quoted, August 22nd, 2018)
- “University Alabama Wins 2018 SEC Student Cyber Challenge Competition”
– SECU News, Auburn, AL (Mentioned for poster competition, April 9th, 2018)
- “Students Place Third in Cyber Defense Competition”
– Computer & Information Science & Engineering News, University of Florida (Quoted, April 10th, 2017)
- “CISE Students Win at 2017 FICS Research Conference on Cybersecurity”
– Computer & Information Science & Engineering News, University of Florida (Quoted, April 3rd, 2017)
- “17 ways the Internet of Things can go horribly wrong”
– ZDNet (Mentioned, March 21st, 2016)
- “UCF Cyber Defense Turns Smart Thermostat Into Potential Spy”
– UCF Today (Mentioned, August 11th, 2014)
- “A used thermostat could hack your house”
– CNN Money (Interviewed (video), August 7th, 2014)
- “Is your Watch or Thermostat a Spy? Cybersecurity Firms are on it” NPR
– All Things Considered (Interviewed (voice), August 6th, 2014)
- “Nest Hackers Will Offer Tool To Keep The Google-Owned Company From Getting Users’ Data”
– Forbes Tech (Interviewed, July 16th, 2014)
- “UCF wins Raytheon cyber defense contest”
– Orlando Sentinel (Mentioned, April 28th, 2014)
- I’m a licensed amateur radio operator – KK4QIS