Cloud Cmputing Security
- 1. Deconstructing Cloud Computing Devyani Bharat Vaidya Polytechnic Student
- 2. The Problem with Emerging Technologies • No history of vulnerabilities and attacks to fall back o n • No institutional knowledge • “I need the security requirements by 5 pm today” • Will it be sustaining/evolutionary, disruptive, or simp ly fail? • Easy to get bogged down in the new stuff, and forget the fundamentals!
- 3. NIST Definition • On-demand self-service. • Broad network access. • Resource pooling. • Rapid elasticity. • Measured Service. • Does this really help us as auditors and security profe ssionals?
- 4. Architecture and Service Definitions • Three Cloud Service Delivery Models: 1. Infrastructure as a Service (IaaS) 2. Platform as a Service (PaaS) 3. Software as a Service (SaaS) • Four Cloud Service Deployment Models 1. Public 2. Private 3. Community 4. Hybrid
- 5. CSA Cloud Reference Model
- 6. Hypervisors • Runs multiple instances of an OS (or multiple OSes) on shared hardware • Native or “bare metal” – PR/SM on the IBM System 370 (1972!) – VMWare ESXi – Microsoft Hyper-V • Host based – Virtual PC – VMWare Server – Parallels • Can use direct physical storage and/or virtual disks • Mainly used for IaaS and PaaS
- 8. What is Important Here? • Know where your organization ends and the other b egins – Patching, software licensing, data retention, etc. • Make sure that there is documented responsibility fo r EVERY layer in the cloud stack – “Hey man, it’s my responsibility to patch the hypervisors n ot the OSes.”
- 9. Threat Modeling 101 • Systematic way to develop requirements, test plans and testing tools • Three basic ways to approach a threat model: attack focused, asset focused, design focused • Model can be represented in many ways, including U ML, attack trees, and data flow diagrams • Microsoft Security Development Life Cycle (SDL), OC TAVE, Trike • Pick and choose what works best for your organizati on.
- 10. Examples
- 11. Cloud Computing Threat Model ENISA Cloud Computing Risk Assessment
- 12. Threat Model • Risk 1: Resource Exhaustion* • Risk 2: Customer Isolation Failure* • Risk 3: Management Interface Compromise • Risk 4: Interception of Data in Transmission • Risk 5: Data leakage on Upload/Download, Intra-clou d
- 13. Threat Model • Risk 6: Insecure or Ineffective Deletion of Data* • Risk 7: Distributed Denial of Service (DDoS) • Risk 8: Economic Denial of Service* • Risk 9: Loss or Compromise of Encryption Keys • Risk 10: Malicious Probes or Scans
- 14. Threat Model • Risk 11: Compromise of Service Engine/Hypervisor* • Risk 12: Conflicts between customer hardening proce dures and cloud environment • Risk 13: Subpoena and E-Discovery* • Risk 14: Risk from Changes of Jurisdiction* • Risk 15: Licensing Risks*
- 15. Threat Model • Risk 16: Network Failure • Risk 17: Networking Management • Risk 18: Modification of Network Traffic • Risk 19: Privilege Escalation* • Risk 20: Social Engineering Attacks
- 16. Threat Model • Risk 21: Loss or Compromise of Operation Logs • Risk 22: Loss or compromise of Security Logs • Risk 23: Backups Lost or Stolen • Risk 23: Unauthorized Access to Premises, Including Physical Access to Machines and Other Facilities • Risk 25: Theft of Computer Equipment.*
- 17. AAA • Insecure storage of cloud access credentials by custo mer • Insufficient roles available • Credentials stored on a transitory machine • Password-based authentication may become insuffici ent – Strong or two-factor authentication for accessing cloud res ources will be necessary
- 18. User Provisioning • Customer cannot control provisioning process • Identity of customer or billing information is not adequately v erified at registration • Delays in synchronization between cloud system components • Multiple, unsynchronized copies of identity data are made • Credentials are vulnerable to interception and replay • De-provisioned credentials are still valid due to time delays in roll-out of revocation
- 19. Remote Access To Management Interface • Allows vulnerabilities in end-point machines to comp romise the cloud infrastructure (single customer or C P) through, for example, weak authentication of resp onses and requests.
- 20. Hypervisor • Exploiting the hypervisor potentially means exploitin g every VM! • Guest to host escape • VM hopping • Virtual machine-based rootkits
- 21. Lack of Resource Isolation • Side channel attacks • Shared storage • Insecure APIs • Lack of tools to enforce resource utilization
- 22. Lack of Reputation Isolation • Activities from one customer impact the reputation of another customer • And can impact the reputation of the CP
- 23. Communication Encryption • Reading data in transit via MITM attacks • Poor authentication • Acceptance of self-signed certificates
- 24. Weak or No Encryption • Data in transit • Data held in archives and databases • Un-mounted virtual machine images • Forensic images and data, sensitive logs and other da ta at rest puts customer data at risk
- 25. Unable to Process Data in Encrypted Form • Encrypting data at rest is easy, but implementing homomorph ic encryption is not -- there is little prospect of any commercia l system being able to maintain data encryption during proces sing. • Bruce Schneier estimates that performing a web search with e ncrypted keywords would increase the amount of computing time by about a trillion.
- 26. Poor Encryption Key Management • Hardware security modules (HSM) required in multip le locations • Key management interfaces which are accessible via the public Internet • The rapid scaling of certificate authorities issuing key pairs to new virtual machines • Revocation of keys for decommissioned virtual machi nes
- 27. Low Entropy for Random Number Generation • The combination of standard system images, virtualiz ation technologies and a lack of input devices means that virtual systems have much less entropy than ph ysical RNGs!
- 28. Inaccurate Modeling of Resource Usage • Overbooking or over-provisioning • Failure of resource allocation algorithms due to extra ordinary events (e.g., outlying news events for conte nt delivery). • Failure of resource allocation algorithms using job or packet classification because resources are poorly cla ssified. • Failures in overall resource provisioning (as opposed to temporary overloads)
- 29. No Control of Vulnerability Assessment Process • Restrictions on port scanning and vulnerability testin g are an important vulnerability which, combined wit h a AUP which places responsibility on the customer for securing elements of the infrastructure, is a serio us security problem.
- 30. Internal (Cloud) Network Probing • Cloud customers can perform port scans and other t ests on other customers within the internal network.
- 31. Co-residence Checks • Side-channel attacks exploiting a lack of resource isol ation allow attackers to determine which resources a re shared by which customers.
- 32. Lack of Forensic Readiness • While the cloud has the potential to improve forensi c readiness, many providers do not provide appropri ate services and terms of use to enable this.
- 33. Media Sanitization • Shared tenancy of physical storage resources means that sensitive data may leak because data destructio n policies may be impossible to implement • Media cannot be physically destroyed because a disk is still being used by another tenant • Customer storage cannot be located or tracked as it moves through the cloud
- 34. SLA • Clauses with conflicting promises to different stakeh olders • Clauses may also be in conflict with promises made b y other clauses or clauses from other providers.
- 35. Audit or Certification Not Available to Customers • The CP cannot provide any assurance to the custome r via audit certification. • Open source hypervisors or customized versions of t hem (e.g., Xen) may not have Common Criteria certifi cation, etc.
- 36. Certification Schemes Not Adapted to Cloud • Very few if any cloud-specific control, which means t hat security vulnerabilities are likely to be missed.
- 37. Inadequate Resource Provisioning and Investme nts in Infrastructure • Infrastructure investments take time. If predictive m odels fail, the cloud provider service can fail for a lon g period.
- 38. No Policies for Resource Capping • If there is not a flexible and configurable way for the customer and/or the cloud provider to set limits on r esources, this can be problematic when resource use is unpredictable.
- 39. Storage of Data in Multiple Jurisdictions • Mirroring data for delivery by edge networks and red undant storage without real-time information availa ble to the customer of where data is stored.
- 40. Lack of Information on Jurisdictions • Data may be stored and/or processed in high risk juri sdictions where it is vulnerable to confiscation by for ced entry.
- 41. Lack of Cloud Security Awareness • Cloud customers and providers are not aware of the risks they could face when migrating into the cloud, particularly those risks that are generated from cloud specific threats, i.e. loss of control, vendor lock-in, ex hausted CP resources, etc.
- 42. Lack of Vetting Processes • Since there may be very high privilege roles within cl oud providers, due to the scale involved, the lack or i nadequate vetting of the risk profile of staff with suc h roles is an important vulnerability.
- 43. Unclear Roles and Responsibilities • Inadequate definition of roles and responsibilities in the cloud provider organization.
- 44. Poor Enforcement of Role Definitions • Within the cloud provider, a failure to segregate role s may lead to excessively privileged roles which can make extremely large systems vulnerable.
- 45. Need-to-know Principle Not Applied • Poorly defined roles and responsibilities • Parties should not be given unnecessary access to da ta.
- 46. Inadequate Physical Security Procedures • Lack of physical perimeter controls (smart card authe ntication at entry); • Lack of electromagnetic shielding for critical assets v ulnerable to eavesdropping.
- 47. Mismanagement • System or OS vulnerabilities • Untrusted software • Lack of - or a poor and untested - business continuity and disaster recover y plan • Lack of - or incomplete or inaccurate - asset inventory • Lack of - or poor or inadequate - asset classification • Unclear asset ownership
- 48. Poor Identification of Project Requirements • Lack of consideration of security and legal complianc e requirements • No systems and applications user involvement • Unclear or inadequate business requirements.
- 49. Application Vulnerabilities and Poor Patch Mana gement • Bugs in the application code • Conflicting patching procedures between provider an d customer • Application of untested patches • Vulnerabilities in browsers • Dormant virtual machines • Outdated virtual machine templates
- 50. Additional Vulnerabilities • Resource consumption vulnerabilities • Breach of NDA by provider • Liability from data loss (cp) • Lack of policy or poor procedures for logs collection and retention • Inadequate or misconfigured filtering resources
- 51. Resources • ENISA -- Cloud Computing Risk Assessment: http://www.enisa. europa.eu/act/rm/files/deliverables/cloud-computing-risk-ass essment • NIST Cloud Computing: http://csrc.nist.gov/groups/SNS/cloud -computing/ • Cloud Security Alliance: http://www.cloudsecurityalliance.org / • Microsoft SDL: http://www.microsoft.com/security/sdl/ • OCTAVE: http://www.cert.org/octave/ • QwestBusiness Blog: http://www.qwest.com/business/blog/