Safe Exam Browser Security Research
Penetration testing of lockdown browsers with responsible vulnerability disclosure
Overview
As part of the Computer & Network Security course at TU/e, our team conducted comprehensive security research on Safe Exam Browser (SEB), a widely-used lockdown browser for secure online examinations. Our research uncovered multiple critical vulnerabilities that could allow students to bypass security restrictions.
Responsible Disclosure: All vulnerabilities were reported to the SEB development team following responsible disclosure practices. Our findings were acknowledged in the official SEB v3.6.0 release notes.
The Challenge
Safe Exam Browser is designed to create a secure testing environment by:
- Preventing access to other applications and system functions
- Blocking keyboard shortcuts and system commands
- Monitoring for prohibited processes and activities
- Creating a kiosk mode that locks down the entire system
Our goal was to identify weaknesses in these security mechanisms that could potentially be exploited by malicious actors.
Solution
Vulnerability Classes Discovered
1. Process Injection Vulnerabilities
Discovered methods to inject code into the SEB process, allowing bypass of security restrictions and access to prohibited system functions.
2. Privilege Escalation
Found ways to elevate privileges within the SEB environment, enabling access to administrator-level functions while appearing to run in restricted mode.
3. Memory Manipulation
Identified techniques to modify SEB's runtime memory to disable security checks and monitoring functions without triggering detection.
4. Configuration Bypass
Discovered methods to override secure configuration settings, allowing modification of exam parameters and security policies.
5. Network Communication Interception
Found ways to intercept and modify network communications between SEB and exam servers, potentially allowing manipulation of exam data.
Technical Implementation
Research Methodology
Static Analysis
- • Reverse engineered SEB binaries using IDA Pro and x64dbg
- • Analyzed .NET assemblies with dnSpy and ILSpy
- • Identified critical security functions and bypass points
- • Mapped out the security architecture and trust boundaries
Dynamic Analysis
- • Monitored runtime behavior with Process Monitor and API Monitor
- • Performed DLL injection and hooking experiments
- • Tested various bypass techniques in controlled environments
- • Validated exploits across different Windows versions
Proof of Concept Development
- • Created minimal PoCs for each vulnerability class
- • Documented exploitation steps and requirements
- • Developed mitigation recommendations
- • Prepared detailed technical report for developers
Project Details
- Role
- Security Researcher
- Context
- University Course Project
- Timeline
- Apr 2023 - Jun 2023
- Client
- TU/e Computer & Network Security Course
Tech Stack
Tools & Techniques
Impact
Key Achievements
Impact & Recognition
- • All vulnerabilities responsibly disclosed to SEB development team
- • Acknowledged in official SEB v3.6.0 release notes
- • Contributed to improved security for millions of exam takers
- • Received top grade for the security research project
- • Developed patches and mitigation strategies for each vulnerability
Key Takeaways
This research highlighted the importance of:
- • Defense in depth - single security mechanisms are insufficient
- • Regular security audits of critical software
- • Responsible disclosure practices in vulnerability research
- • Collaboration between researchers and developers