0.0
NA
CVE-2021-47383
Linux TTY Out-of-Bounds Vulnerability
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.

INFO

Published Date :

May 21, 2024, 3:15 p.m.

Last Modified :

May 21, 2024, 4:54 p.m.

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Remotely Exploitable :

No

Impact Score :

Exploitability Score :

Affected Products

The following products are affected by CVE-2021-47383 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-47383.

URL Resource
https://git.kernel.org/stable/c/067c694d06040db6f0c65281bb358452ca6d85b9
https://git.kernel.org/stable/c/3b0c406124719b625b1aba431659f5cdc24a982c
https://git.kernel.org/stable/c/699d926585daa6ec44be556cdc1ab89e5d54557b
https://git.kernel.org/stable/c/70aed03b1d5a5df974f456cdc8eedb213c94bb8b
https://git.kernel.org/stable/c/7e71fcedfda6f7de18f850a6b36e78d78b04476f
https://git.kernel.org/stable/c/883f7897a25e3ce14a7f274ca4c73f49ac84002a
https://git.kernel.org/stable/c/8a6a240f52e14356386030d8958ae8b1761d2325
https://git.kernel.org/stable/c/d570c48dd37dbe8fc6875d4461d01a9554ae2560

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-47383 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-47383 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    May. 28, 2024

    Action Type Old Value New Value
  • CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    May. 21, 2024

    Action Type Old Value New Value
    Added 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.
    Added Reference kernel.org https://git.kernel.org/stable/c/7e71fcedfda6f7de18f850a6b36e78d78b04476f [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/70aed03b1d5a5df974f456cdc8eedb213c94bb8b [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/067c694d06040db6f0c65281bb358452ca6d85b9 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/8a6a240f52e14356386030d8958ae8b1761d2325 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/883f7897a25e3ce14a7f274ca4c73f49ac84002a [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/d570c48dd37dbe8fc6875d4461d01a9554ae2560 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/699d926585daa6ec44be556cdc1ab89e5d54557b [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/3b0c406124719b625b1aba431659f5cdc24a982c [No types assigned]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-47383 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-47383 weaknesses.

NONE - Vulnerability Scoring System
: