CVE-2021-22600:Double free vulnerability in Linux kernel's packet_set_ring() function allows local privilege escalation.

splash
Back

Description Preview

CVE-2021-22600 is a critical vulnerability in the Linux kernel's networking subsystem, specifically in the packet_set_ring() function located in net/packet/af_packet.c. This vulnerability is classified as a double free issue (CWE-415), where memory is freed twice, potentially leading to memory corruption. Local attackers can exploit this vulnerability through carefully crafted syscalls to either escalate privileges to gain root access or cause a denial of service condition by crashing the system. This vulnerability affects multiple Linux kernel versions and has been addressed in kernel versions after the patch was applied.

Overview

The vulnerability exists in the packet socket implementation of the Linux kernel. When handling packet sockets, the packet_set_ring() function can incorrectly free memory that has already been freed under certain conditions. This double free condition can be triggered by a local user with the ability to make specific syscalls. When successfully exploited, an attacker could gain elevated privileges on the system or cause system instability resulting in denial of service. The vulnerability is particularly concerning as it affects a core component of the Linux kernel and can be exploited by local users without requiring special privileges.

Remediation

To address this vulnerability, system administrators should:

  1. Update the Linux kernel to a version that includes the fix (commit ec6af094ea28f0f2dda1a6a33b14cd57e36a9755).
  2. If updating is not immediately possible, consider applying the patch manually to affected systems.
  3. For Debian systems, apply the security updates referenced in DSA-5096 or DLA 2941-1 for Debian LTS.
  4. Monitor systems for unusual behavior that might indicate exploitation attempts.
  5. Restrict local access to trusted users only until the patch can be applied.
  6. Consider implementing additional access controls to limit who can interact with packet sockets.

References

  1. Linux kernel patch: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=ec6af094ea28f0f2dda1a6a33b14cd57e36a9755
  2. Debian LTS security announcement: https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html
  3. Debian security advisory DSA-5096: https://www.debian.org/security/2022/dsa-5096
  4. NetApp security advisory: https://security.netapp.com/advisory/ntap-20230110-0002/

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

Focus on What Matters

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

Let's talk!

background
Armis Vulnerability Intelligence Database