Junior Vulnerability Researcher (5G & Protocol Security)

CACI International Inc; Florham Park (NJ); On-site; USD 79,400 - 162,700; Full time

Benefits offered by this job

Healthcare benefits

Financial support

Continuing education opportunities

Time off benefits

Job summary

A telecommunications security firm is seeking a Junior Vulnerability Researcher to join its 5G security team in Florham Park, NJ. The role involves researching security flaws in 3GPP protocols and proprietary binaries, developing tools for protocol decoding, and analyzing telecom infrastructures. Candidates must have a Top Secret clearance and experience in software exploitation or reverse engineering with strong C/C++ and Python skills. The position offers competitive compensation and comprehensive benefits.

Qualifications

• Active Top Secret clearance required.
• 3–5 years of experience in relevant fields.
• Strong C/C++ and Python3 skills.

Responsibilities

• Research 3GPP protocols to identify flaws.
• Analyze telecom binaries and firmware.
• Develop custom scripts for protocol decoding.

Skills

Software exploitation

Reverse engineering

Protocol development

C/C++ proficiency

Python3 scripting

4G/5G architecture knowledge

Network protocols knowledge

IDA Pro or Ghidra experience

Binary analysis understanding

Tools

Wireshark

Binary Ninja

Job description

Job Title: Junior Vulnerability Researcher (5G & Protocol Security) – Job Category: Engineering – Time Type: Full time – Minimum Clearance Required to Start: Top Secret – Employee Type: Regular – Percentage of Travel Required: None – Type of Travel: None

The Opportunity

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 3GPP protocols and proprietary telecom binaries while developing the automated tooling necessary to secure national mobile infrastructure.

Responsibilities

• Execute research into 3GPP 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 (e.g., Wireshark) to inspect protocol traffic and hardware state.
• Document research findings and contribute to the development of technical security reports.

Qualifications

Required

• 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 Python3.
• 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.

Desired

• 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.

Pay Range

Proposed Salary Range: $79,400 - $162,700

We offer competitive compensation, benefits and learning and development opportunities. Our broad and competitive mix of benefits options is designed to support and protect employees and their families, including healthcare, wellness, financial, retirement, family support, continuing education, and time off benefits.

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.