high CVSS 7.8 EPSS <0.1%

CVE-2023-52649·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: drm/vkms: Avoid reading beyond LUT array When the floor LUT index (drm_fixp2int(lut_index) is the last index of the array the ceil LUT index will point to an entry beyond the array. Make sure we guard against it and use the value of the floor LUT index. v3: - Drop bits from commit description that didn't contribute anything of value

Severity
high
Software
Kernel
Fixed in
6.8.2
Published

How likely is exploitation

FIRST's Exploit Prediction Scoring System puts the probability of this CVE being exploited in the next 30 days at <0.1% — higher than 6% of all published CVEs. EPSS is an independent forecast of exploitation, not a severity rating: it says nothing about how much damage a successful attack does, which is what a CVSS score measures.

Read the two together. CVE-2023-52649 scores 7.8 on CVSS, so a successful attack would be serious — but at <0.1%, almost nobody is currently attempting it. That is a different situation from a flaw under mass exploitation, and it is usually the difference between patching on your next maintenance window and patching tonight.

Affected versions

From: 6.8

Until: 6.8.2

Fixed in: 6.8.2

How to fix this CVE

Update your Linux kernel to version 6.8.2 or later to resolve this array bounds vulnerability in the DRM VKMS (Virtual Kernel Modesetting) subsystem. The vulnerability occurs when the LUT (Look-Up Table) interpolation logic attempts to read beyond allocated array boundaries during color space calculations. Apply the kernel update through your distribution's package manager and reboot to activate the patched version.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Step 1: Check your running kernel version with: uname -r
  2. Step 2: Verify if VKMS is loaded by running: lsmod | grep vkms
  3. Step 3: Check kernel logs for memory access errors near drm_fixp2int or LUT operations: dmesg | grep -E '(vkms|LUT|lut_index)'
  4. Step 4: After patching, confirm the fix with: uname -r and verify the version is 6.8.2 or newer

FAQ

What is CVE-2023-52649?

This vulnerability exists in the Linux kernel's VKMS (Virtual Kernel Modesetting) graphics driver where the color lookup table (LUT) interpolation code fails to properly validate array bounds, potentially reading memory beyond the allocated LUT array when the floor index equals the array size.

Is CVE-2023-52649 being actively exploited?

No, this vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog and no public exploits are available. However, the high CVSS score warrants timely patching.

What versions of Kernel are affected by CVE-2023-52649?

Linux kernel versions 6.8 through 6.8.2 are vulnerable. The issue was resolved in kernel version 6.8.2 and later releases.

How do I check if my server is vulnerable to CVE-2023-52649?

Run 'uname -r' to check your kernel version. If it reports 6.8, 6.8.1, or 6.8.2 without a patch level, you are vulnerable. Additionally, check if VKMS is in use with 'lsmod | grep vkms'.

Does Defensia detect CVE-2023-52649?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2023-52649 will appear in your dashboard with remediation steps.

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References

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