CVE-2021-47383

Aliases:UBUNTU-CVE-2021-47383DEBIAN-CVE-2021-47383
Advisory lineage Upstream: 0 Downstream: 78
Modified
Published: 21 May 2024, 15:03
Last modified:05 Aug 2026, 08:47

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
v3.1 (cve.org)
EPSS Score
0.27% LOW
0% probability +0.26%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

21 May 2024, 15:03
Published
Vulnerability first disclosed
05 Aug 2026, 08:47
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: tty: Fix out-of-bound vmalloc access in imageblit This issue happens when a userspace program does an ioctl FBIOPUT_VSCREENINFO passing the fb_var_screeninfo struct containing only the fields xres, yres, and bits_per_pixel with values. If this struct is the same as the previous ioctl, the vc_resize() detects it and doesn't call the resize_screen(), leaving the fb_var_screeninfo incomplete. And this leads to the updatescrollmode() calculates a wrong value to fbcon_display->vrows, which makes the real_y() return a wrong value of y, and that value, eventually, causes the imageblit to access an out-of-bound address value. To solve this issue I made the resize_screen() be called even if the screen does not need any resizing, so it will "fix and fill" the fb_var_screeninfo independently.

CVSS Metrics

  • v3.1•HIGH•Score: 7.1CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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

EPSS Trends

Current EPSS score: 0.27%• Percentile: 19%

Techniques & Countermeasures

  • CWE-125•Out-of-bounds Read

    The product reads data past the end, or before the beginning, of the intended buffer.

Affected Systems

  • debian•linux

    < 5.10.84-1 | < 5.14.12-1 | < 5.14.12-1 | < 5.14.12-1

  • ubuntu•linux

    all | < 4.15.0-163.171 | < 5.4.0-91.102

  • ubuntu•linux-allwinner-5.19

    all

  • ubuntu•linux-aws

    all | < 4.15.0-1116.123 | < 5.4.0-1060.63

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    all

  • ubuntu•linux-aws-5.13

    all

  • ubuntu•linux-aws-5.19

    all

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.4

    < 5.4.0-1060.63~18.04.1

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-aws-6.2

    all

  • ubuntu•linux-aws-fips

    < 4.15.0-2057.59 | all | < 5.4.0-1069.73+fips2

  • ubuntu•linux-aws-hwe

    < 4.15.0-1116.123~16.04.1

  • ubuntu•linux-azure

    < 4.15.0-1127.140~14.04.1 | < 4.15.0-1127.140~16.04.1 | all | < 5.4.0-1064.67

  • ubuntu•linux-azure-4.15

    < 4.15.0-1127.140

  • ubuntu•linux-azure-5.11

    all

  • ubuntu•linux-azure-5.13

    all

  • ubuntu•linux-azure-5.19

    all

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.4

    < 5.4.0-1064.67~18.04.1

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-6.2

    all

  • ubuntu•linux-azure-edge

    all

  • ubuntu•linux-azure-fde

    all

  • ubuntu•linux-azure-fde-5.15

    < 5.15.0-1114.123~20.04.1

  • ubuntu•linux-azure-fde-5.19

    all

  • ubuntu•linux-azure-fde-6.2

    all

  • ubuntu•linux-azure-fips

    < 4.15.0-2039.43 | all | < 5.4.0-1073.76+fips1

  • ubuntu•linux-bluefield

    all | < 5.4.0-1022.25

  • ubuntu•linux-fips

    all | < 4.15.0-1073.82 | < 5.4.0-1037.43

  • ubuntu•linux-gcp

    < 4.15.0-1112.126~16.04.1 | all | < 5.4.0-1058.62

  • ubuntu•linux-gcp-4.15

    < 4.15.0-1112.126

  • ubuntu•linux-gcp-5.11

    all

  • ubuntu•linux-gcp-5.13

    all

  • ubuntu•linux-gcp-5.19

    all

  • ubuntu•linux-gcp-5.3

    all

  • ubuntu•linux-gcp-5.4

    < 5.4.0-1058.62~18.04.1

  • ubuntu•linux-gcp-5.8

    all

  • ubuntu•linux-gcp-6.2

    all

  • ubuntu•linux-gcp-fips

    < 4.15.0-2022.24 | all | < 5.4.0-1067.71~20.04.1

  • ubuntu•linux-gke

    all

  • ubuntu•linux-gke-4.15

    all

  • ubuntu•linux-gke-5.15

    all

  • ubuntu•linux-gke-5.4

    all

  • ubuntu•linux-gkeop

    < 5.4.0-1027.28

  • ubuntu•linux-gkeop-5.4

    all

  • ubuntu•linux-hwe

    < 4.15.0-163.171~16.04.1 | all

  • ubuntu•linux-hwe-5.11

    all

  • ubuntu•linux-hwe-5.13

    all

Showing first 50 affected entries in server-rendered view.

References (12)