Vulnerabilities and Safeguards in Networks with QoS Support

1. Vulnerabilities and Safeguards in Networks with QoS Support Dr. Sonia Fahmy CS Dept., Purdue University

2. Goals • Study, classify and rank vulnerabilities in a QoS enabled network. • Model the various possible attacks and determine their effect on QoS experimentally. • Design usable, easily deployable and configurable, adaptive/reactive safeguards for such attacks, and study the tradeoffs involved.

3. Proposed Research • Study QoS, policy control and network security mechanisms in detail and formulate attacks possible in a QoS enabled network. • Study network simulation tools, model attacks and measure damage and performance loss • Implement the attacks on a QoS network test bed and evaluate damage and performance.

4. Proposed Research • Propose recommendations for safeguards against attacks. • Implement these safeguards both in simulated and actual networks. • measure their performance. • convert them to tools.

5. Possible Solutions • Using trustable entities. • Authentication mechanisms. • Securing policy control. • Constant monitoring of QoS provisioning. • Proposing design changes to make QoS networks inherently secure.

6. Components of QoS • Resource allocation • Admission and policy control • QoS based routing • Resource reservation • Resource usage and provisioning • Traffic shaping and policing • Buffer management and scheduling • Congestion Control • Traffic monitoring and Feedback

7. Quality of Service

8. QoS Categories • Differentiated Services(DiffServ) • Classification at edges • Core only forwards • Potential points of attack • DSCP field and services based on it • QoS negotiations across edge routers • PHB, PHB groups, EF, AF

10. Components of QoS • Integrated Services • Best Effort Service • Controlled-Load Service: Performance as good as in an unloaded datagram network. No quantitative assurances • Guaranteed Service: • Firm bound on data throughput and delay. • Every element along the path must provide delay bound. • Is not always implementable, e.g., Shared Ethernet.

12. Policy Control • COPS protocol • PEPs and PDPs and their role

13. Network Security • Denial of service • Service overloading by flooding • Compromising routers by altering routing strategies • Exploit flaws in software implementation • Session Hijacking • Masquerading • Information Leakage • Unauthorized resource usage (Theft of service).

14. Security Issues • Attack Operations • Inject(I), Modify(M), Delay(Dl), Drop(Dr), Eavesdrop(E) • Points of Attack • Policy control mechanisms • Congestion control mechanisms • Resource configuration in routers • Resource usage in routers

15. Security Issues • Vulnerabilities Exploited • Design problems (eg. DSCP uncovered, SYN flooding) • Implementation issues (poor software, buffer overflow) • Interoperability issues • Complementary protocols

16. Types of Security Breaches • Theft of Service (Unauthorized use) • Modifying DSCP (M) • Injecting RSVP signaling messages (I) • Injecting malicious configuration (I) • Denial of Service • Compromising routers (Dr, Dl) • Re-marking packets (M) • Flooding (I)

17. Types of Security Breaches • Information Leakage • About QoS policies (E) • Data that goes through QoS enabled Network (E) • Session Hijacking / Masquerading • Seizing control of a session by injecting or maliciously modifying authentication packets (I and M)

18. Recommendations • Building good policy mechanisms • Securing PEPs like Edge routers and BBs (Authentication) • Encapsulation/Encryption important fields • Performing QoS measurements

19. Tools • Monitoring Resource Allocation • Monitoring signaling mechanisms • Monitoring QoS negotiations • Monitoring packet classifiers • Monitoring Resource Usage • Monitoring bandwidth utilization • Monitoring remarking of service levels • Monitoring routing strategies