cbcvebase.
CVE-2021-47383
published 2024-05-21

CVE-2021-47383: 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…

PriorityP430high7.1CVSS 3.1
AVLACLPRLUINSUCHINAH
EPSS
0.26%
18.2th percentile
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.

Affected

21 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 5.14.12-1 (bookworm)linux 5.14.12-1 (bookworm)
linuxlinux
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 7e71fcedfda6f7de18f850a6b36e78d78b04476f7e71fcedfda6f7de18f850a6b36e78d78b04476f
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 70aed03b1d5a5df974f456cdc8eedb213c94bb8b70aed03b1d5a5df974f456cdc8eedb213c94bb8b
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 067c694d06040db6f0c65281bb358452ca6d85b9067c694d06040db6f0c65281bb358452ca6d85b9
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 8a6a240f52e14356386030d8958ae8b1761d23258a6a240f52e14356386030d8958ae8b1761d2325
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 883f7897a25e3ce14a7f274ca4c73f49ac84002a883f7897a25e3ce14a7f274ca4c73f49ac84002a
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < d570c48dd37dbe8fc6875d4461d01a9554ae2560d570c48dd37dbe8fc6875d4461d01a9554ae2560
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 699d926585daa6ec44be556cdc1ab89e5d54557b699d926585daa6ec44be556cdc1ab89e5d54557b
linuxlinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 3b0c406124719b625b1aba431659f5cdc24a982c3b0c406124719b625b1aba431659f5cdc24a982c
linuxlinux_kernel< 4.4.2864.4.286
linuxlinux_kernel>= 0 < 5.10.84-15.10.84-1
linuxlinux_kernel>= 0 < 5.14.12-15.14.12-1
linuxlinux_kernel>= 0 < 5.14.12-15.14.12-1
linuxlinux_kernel>= 0 < 5.14.12-15.14.12-1
linuxlinux_kernel>= 4.10 < 4.14.2494.14.249
linuxlinux_kernel>= 4.15 < 4.19.2094.19.209
linuxlinux_kernel>= 4.20 < 5.4.1515.4.151
linuxlinux_kernel>= 4.5 < 4.9.2854.9.285
linuxlinux_kernel>= 5.11 < 5.14.105.14.10
linuxlinux_kernel>= 5.5 < 5.10.715.10.71

CVSS provenance

nvdv3.17.1HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
osv7.1HIGH
vendor_debian7.1HIGH
vendor_redhat7.1HIGH
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.