CVE-2021-3752:Use-after-free vulnerability in Linux kernel's Bluetooth subsystem allows local privilege escalation or system crash.

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A use-after-free vulnerability (CVE-2021-3752) was discovered in the Linux kernel's Bluetooth subsystem. The flaw occurs due to a race condition when a user simultaneously calls connect to a socket and disconnect. This vulnerability can be exploited by a local attacker to cause a system crash (denial of service) or potentially escalate privileges on the affected system. The vulnerability poses significant threats to system confidentiality, integrity, and availability.

Overview

CVE-2021-3752 is a race condition vulnerability (CWE-362) in the Linux kernel's Bluetooth implementation. The issue occurs when connect and disconnect operations are executed simultaneously on a Bluetooth socket, leading to a use-after-free condition. This vulnerability can be triggered by a local user with access to Bluetooth functionality. When successfully exploited, an attacker could cause system instability, crash the kernel, or potentially gain elevated privileges on the system. This vulnerability affects various Linux distributions including Debian and Red Hat-based systems.

Remediation

To address this vulnerability, system administrators should:

  1. Update the Linux kernel to a patched version as provided by your distribution vendor.
  2. Apply security patches released by your Linux distribution for this specific vulnerability.
  3. If immediate patching is not possible, consider temporarily disabling Bluetooth functionality on critical systems until patches can be applied.
  4. Monitor system logs for any unusual Bluetooth-related activities or crashes.
  5. Follow vendor-specific guidance from Red Hat, Debian, Oracle, or NetApp as applicable to your environment.
  6. Restrict physical access to systems where possible, as this vulnerability requires local access to exploit.

References

  1. Red Hat Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1999544
  2. Linux Kernel Mailing List discussion: https://lore.kernel.org/lkml/20211115165435.133245729%40linuxfoundation.org/
  3. OSS Security mailing list: https://www.openwall.com/lists/oss-security/2021/09/15/4
  4. Debian Security Advisory: https://www.debian.org/security/2022/dsa-5096
  5. Debian LTS Announcements:
    • https://lists.debian.org/debian-lts-announce/2022/03/msg00011.html
    • https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html
  6. NetApp Security Advisory: https://security.netapp.com/advisory/ntap-20220318-0009/
  7. Oracle Critical Patch Update: https://www.oracle.com/security-alerts/cpujul2022.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. Health Care & Social Assistance
    Health Care & Social Assistance
  2. Manufacturing
    Manufacturing
  3. Public Administration
    Public Administration
  4. Educational Services
    Educational Services
  5. Finance and Insurance
    Finance and Insurance
  6. Professional, Scientific, & Technical Services
    Professional, Scientific, & Technical Services
  7. Transportation & Warehousing
    Transportation & Warehousing
  8. Utilities
    Utilities
  9. Retail Trade
    Retail Trade
  10. Other Services (except Public Administration)
    Other Services (except Public Administration)
  11. Information
    Information
  12. Arts, Entertainment & Recreation
    Arts, Entertainment & Recreation
  13. Management of Companies & Enterprises
    Management of Companies & Enterprises
  14. Accommodation & Food Services
    Accommodation & Food Services
  15. Construction
    Construction
  16. Mining
    Mining
  17. Real Estate Rental & Leasing
    Real Estate Rental & Leasing
  18. Agriculture, Forestry Fishing & Hunting
    Agriculture, Forestry Fishing & Hunting
  19. Administrative, Support, Waste Management & Remediation Services
    Administrative, Support, Waste Management & Remediation Services
  20. Wholesale Trade
    Wholesale Trade

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Armis Vulnerability Intelligence Database