CVE-2021-47383
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.3% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Weakness
- CWE-125 · Out-of-bounds read
- Record status
- Modified
Affected
- Linux Kernel < 4.4.286
- Linux Kernel < 4.9.285
- Linux Kernel < 4.14.249
- Linux Kernel < 4.19.209
- Linux Kernel < 5.4.151
- Linux Kernel < 5.10.71
- Linux Kernel < 5.14.10
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-47383.md and follow it. Check whether this project is affected by CVE-2021-47383. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- 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
- https://git.kernel.org/stable/c/067c694d06040db6f0c65281bb358452ca6d85b9
- https://git.kernel.org/stable/c/3b0c406124719b625b1aba431659f5cdc24a982c
References
- 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
- 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