CVE-2020-10767:Linux kernel before 5.8-rc1 has a vulnerability in the Enhanced IBPB implementation that could allow local Spectre V2 style attacks.

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A vulnerability was discovered in the Linux kernel before version 5.8-rc1 affecting the implementation of Enhanced IBPB (Indirect Branch Prediction Barrier). The issue causes the IBPB mitigation to be incorrectly disabled when STIBP (Single Thread Indirect Branch Predictors) is not available or when Enhanced IBRS (Indirect Branch Restricted Speculation) is available. This configuration flaw enables local attackers to perform Spectre V2 style attacks, potentially allowing them to access sensitive information through side-channel attacks. The vulnerability primarily impacts system confidentiality by potentially exposing protected memory contents.

Overview

This vulnerability (CVE-2020-10767) affects the Linux kernel's implementation of CPU security mitigations designed to protect against Spectre variant 2 attacks. Specifically, the Enhanced IBPB implementation contains a logic error that disables this important security mitigation in certain hardware configurations. When STIBP is unavailable or Enhanced IBRS is available, the system incorrectly disables IBPB protection, leaving the system vulnerable to branch target injection attacks. This allows a local attacker to potentially extract sensitive information from protected memory areas through speculative execution side-channel attacks. The vulnerability represents a significant security concern for multi-user systems where untrusted users could exploit this flaw to access privileged information.

Remediation

To address this vulnerability, system administrators should:

  1. Update the Linux kernel to version 5.8-rc1 or later, which contains the fix for this issue.
  2. If immediate kernel updates are not possible, apply the specific patch referenced in the kernel commit (21998a351512eba4ed5969006f0c55882d995ada).
  3. For systems that cannot be updated, consider implementing additional access restrictions to limit who can execute code locally on affected systems.
  4. Monitor for unusual system behavior that might indicate exploitation attempts.
  5. Consider implementing additional security layers to protect sensitive data that might be exposed through this vulnerability.

References

  1. Red Hat Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-10767
  2. Linux Kernel Patch: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=21998a351512eba4ed5969006f0c55882d995ada
  3. For more information about Spectre vulnerabilities: https://spectreattack.com/
  4. Linux Kernel Security Team: https://www.kernel.org/doc/html/latest/admin-guide/security-bugs.html

Industry ExposureMost to least
This section illustrates the prevalence of a specific Common Vulnerabilities and Exposures (CVE) across various industries based on customer reports. The ranking displays industries from the most to least affected by this particular vulnerability, offering valuable insight into where this CVE has been most frequently observed. This information can help organizations within these sectors prioritize their security efforts, understand their relative risk exposure compared to their peers, and focus remediation strategies where they are most needed. By understanding the industry-specific impact, organizations can make more informed decisions regarding patching, resource allocation, and overall risk management related to this CVE.

  1. Manufacturing
    Manufacturing
  2. Health Care & Social Assistance
    Health Care & Social Assistance
  3. Public Administration
    Public Administration
  4. Educational Services
    Educational Services
  5. Finance and Insurance
    Finance and Insurance
  6. Retail Trade
    Retail Trade
  7. Professional, Scientific, & Technical Services
    Professional, Scientific, & Technical Services
  8. Transportation & Warehousing
    Transportation & Warehousing
  9. Management of Companies & Enterprises
    Management of Companies & Enterprises
  10. Other Services (except Public Administration)
    Other Services (except Public Administration)
  11. Arts, Entertainment & Recreation
    Arts, Entertainment & Recreation
  12. Utilities
    Utilities
  13. Information
    Information
  14. Construction
    Construction
  15. Real Estate Rental & Leasing
    Real Estate Rental & Leasing
  16. Mining
    Mining
  17. Wholesale Trade
    Wholesale Trade
  18. Accommodation & Food Services
    Accommodation & Food Services
  19. Administrative, Support, Waste Management & Remediation Services
    Administrative, Support, Waste Management & Remediation Services
  20. Agriculture, Forestry Fishing & Hunting
    Agriculture, Forestry Fishing & Hunting

Focus on What Matters

  1. See Everything.
  2. Identify True Risk.
  3. Proactively Mitigate Threats.

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