CVE-2020-27675

Advisory lineage Upstream: 0 Downstream: 15
Modified
Published: 22 Oct 2020, 20:32
Last modified:04 Aug 2024, 16:18

Vulnerability Summary

Overall Risk (default)
low
19/100
CVSS Score
4.7 MEDIUM
v3.1 (nvd)
EPSS Score
0.06% LOW
0% probability -0.03%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

22 Oct 2020, 20:32
Published
Vulnerability first disclosed
04 Aug 2024, 16:18
Last Modified
Vulnerability information updated

Description

An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x. drivers/xen/events/events_base.c allows event-channel removal during the event-handling loop (a race condition). This can cause a use-after-free or NULL pointer dereference, as demonstrated by a dom0 crash via events for an in-reconfiguration paravirtualized device, aka CID-073d0552ead5.

CVSS Metrics

  • v3.1•MEDIUM•Score: 4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
  • v2.0•MEDIUM•Score: 4.7AV:L/AC:M/Au:N/C:N/I:N/A:C

EPSS Trends

Current EPSS score: 0.06%• Percentile: 20%

Techniques & Countermeasures

  • CWE-362•Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

    The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

  • 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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

  • CWE-476•NULL Pointer Dereference

    The product dereferences a pointer that it expects to be valid but is NULL.

Affected Systems

  • debian•debian_linux

    9.0

  • fedoraproject•fedora

    31 | 32 | 33

  • linux•linux_kernel

    ≤ 5.9.1

References (10)