Junior Vulnerability Researcher; 5G & Protocol Security

We are seeking a Vulnerability Researcher to join our 5G security team, focusing on protocol analysis and firmware reverse engineering. This role is for a practitioner with a strong systems background who is ready to take ownership of research tasks within complex telecommunications stacks. You will work as part of a high‑performing group, identifying security flaws in 3

GPP protocols and proprietary telecom binaries while developing the automated tooling necessary to secure national mobile infrastructure.

• Execute research into 3
  
  GPP protocols (NGAP, GTP, etc.) to identify crashes and logic flaws using stateful fuzzing techniques.
• Perform static and dynamic analysis on compiled telecom binaries and firmware to understand undocumented protocol logic.
• Support the development of custom Python3 scripts for protocol decoding and automating analysis of "closed-box" systems.
• Assist in mapping state machines within 5G session management flows using symbolic or concolic execution tools.
• Analyze signaling and data plane components to identify potential attack surfaces in 5G Core and RAN environments.
• Use debugging tools and packet analysis software (Wireshark) to inspect protocol traffic and hardware state.
• Document research findings and contribute to the development of technical security reports.

• An active Top Secret clearance.
• 3–5 years of professional experience in software exploitation, reverse engineering, or protocol development.
• Strong proficiency in C/C++ and scripting experience in Python
  3.
• Working knowledge of 4G/5G architecture and networking protocols (TCP/IP, SCTP, HTTP/2).
• Experience with disassembly tools such as IDA Pro, Ghidra, or Binary Ninja.
• Foundational understanding of binary analysis and memory corruption primitives.
• Demonstrated ability to conduct independent technical research and analyze complex software systems.

• An active SCI clearance.
• Experience with software‑defined radio (SDR) or cellular testing equipment.
• Familiarity with Linux‑based telecom network functions.
• Participation in security research projects or CTFs with a focus on networking or pwnable challenges.

$79,400 - $162,700

CaCI is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, pregnancy, sexual orientation, age, national origin, disability, status as a protected veteran, or any other protected characteristic.