CVE-2020-29569

Advisory lineage Upstream: 0 Downstream: 29
Modified
Published: 15 Dec 2020, 17:00
Last modified:04 Aug 2024, 16:55

Vulnerability Summary

Overall Risk (default)
medium
35/100
CVSS Score
8.8 HIGH
v3.1 (nvd)
EPSS Score
0.21% LOW
0% probability +0.14%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

15 Dec 2020, 17:00
Published
Vulnerability first disclosed
04 Aug 2024, 16:55
Last Modified
Vulnerability information updated

Description

An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped. However, the handler may not have time to run if the frontend quickly toggles between the states connect and disconnect. As a consequence, the block backend may re-use a pointer after it was freed. A misbehaving guest can trigger a dom0 crash by continuously connecting / disconnecting a block frontend. Privilege escalation and information leaks cannot be ruled out. This only affects systems with a Linux blkback.

CVSS Metrics

  • v3.1•HIGH•Score: 8.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
  • v2.0•HIGH•Score: 7.2AV:L/AC:L/Au:N/C:C/I:C/A:C

EPSS Trends

Current EPSS score: 0.21%• Percentile: 43%

Techniques & Countermeasures

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • debian•debian_linux

    9.0 | 10.0

  • linux•linux_kernel

    ≥ 4.1.44, < 4.2 | ≥ 4.4.80, < 4.4.254 | ≥ 4.9.36, < 4.9.249 | ≥ 4.11.9, < 4.12 | ≥ 4.12, < 4.14.213 | ≥ 4.15, < 4.19.164 | ≥ 4.20, < 5.4.86 | ≥ 5.5, < 5.10.4

  • netapp•hci_compute_node_firmware

    na

  • netapp•solidfire_\&_hci_management_node

    na

  • netapp•solidfire_\&_hci_storage_node

    na

  • xen•xen

    ≤ 4.14.1

References (6)