DEBIAN-CVE-2021-47383

Advisory lineage Upstream: 1 Downstream: 0
Upstream
CVE-2021-47383
Published: 21 May 2024, 15:15
Last modified:28 Apr 2026, 20:23

Vulnerability Summary

Overall Risk (default)
medium
28/100
CVSS Score
7.1 HIGH
3.1 (osv_debian)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

21 May 2024, 15:15
Published
Vulnerability first disclosed
28 Apr 2026, 20:23
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

Affected Systems

  • debian•linux

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

References (1)