CVE-2021-3492

Advisory lineage Upstream: 0 Downstream: 4
Modified
Published: 17 Apr 2021, 04:20
Last modified:17 Sept 2024, 03:54

Vulnerability Summary

Overall Risk (default)
medium
40/100
CVSS Score
8.8 HIGH
v3.1 (cve.org)
EPSS Score
24.44% HIGH
24% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

17 Apr 2021, 04:20
Published
Vulnerability first disclosed
17 Sept 2024, 03:54
Last Modified
Vulnerability information updated

Description

Shiftfs, an out-of-tree stacking file system included in Ubuntu Linux kernels, did not properly handle faults occurring during copy_from_user() correctly. These could lead to either a double-free situation or memory not being freed at all. An attacker could use this to cause a denial of service (kernel memory exhaustion) or gain privileges via executing arbitrary code. AKA ZDI-CAN-13562.

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
  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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: 24.44%• Percentile: 96%

Techniques & Countermeasures

  • CWE-415•Double Free

    The product calls free() twice on the same memory address.

  • CWE-401•Missing Release of Memory after Effective Lifetime

    The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

Affected Systems

  • canonical•ubuntu_linux

    < 18.04 | ≥ 18.04.1, < 20.04 | < 20.10

  • ubuntu•linux_kernel

    ≥ 5.8 kernel, < 5.8.0-50.56 | ≥ 5.4 kernel, < 5.4.0-72.80

References (6)