high CVSS 7.8 EPSS 0.26%

CVE-2023-52764·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: media: gspca: cpia1: shift-out-of-bounds in set_flicker Syzkaller reported the following issue: UBSAN: shift-out-of-bounds in drivers/media/usb/gspca/cpia1.c:1031:27 shift exponent 245 is too large for 32-bit type 'int' When the value of the variable "sd->params.exposure.gain" exceeds the number of bits in an integer, a shift-out-of-bounds error is reported. It is triggered because the variable "currentexp" cannot be left-shifted by more than the number of bits in an integer. In order to avoid invalid range during left-shift, the conditional expression is added.

Severity
high
Software
Kernel
Fixed in
6.6.3
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 0.26% — higher than 17% 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-2023-52764 scores 7.8 on CVSS, so a successful attack would be serious — but at 0.26%, 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: 6.6

Until: 6.6.3

Fixed in: 6.6.3

How to fix this CVE

Update your Linux kernel to version 6.6.3 or later to patch a shift-out-of-bounds vulnerability in the CPIA1 camera driver. This issue occurs when improper exposure gain values cause invalid bit-shift operations. Apply the kernel update through your distribution's package manager and reboot the system to activate the patched kernel.

sudo dnf update kernel kernel-devel && sudo reboot

Defensia detects this vulnerability

How to check if you are affected

  1. Check installed kernel version: uname -r (vulnerable if output shows 6.6.0 through 6.6.2)
  2. Verify CPIA1 USB camera driver is loaded: lsmod | grep gspca_cpia (if output is empty, component is not exposed)
  3. Search kernel logs for UBSAN shift-out-of-bounds errors: dmesg | grep -i 'shift-out-of-bounds' or grep 'cpia1' /var/log/kern.log
  4. Confirm kernel patch is applied: cat /proc/version (should show kernel version 6.6.3 or higher after update)

FAQ

What is CVE-2023-52764?

CVE-2023-52764 is a shift-out-of-bounds vulnerability in the Linux kernel's CPIA1 USB camera driver that occurs when exposure gain parameters exceed valid bit-shift ranges, causing undefined behavior and potential kernel instability.

Is CVE-2023-52764 being actively exploited?

No, this vulnerability is not listed on the CISA KEV catalog and has no known public exploits. However, it can still trigger kernel crashes if triggered through malformed USB camera device parameters.

What versions of Kernel are affected by CVE-2023-52764?

Linux kernel versions 6.6.0 through 6.6.2 are vulnerable. The issue was patched starting with kernel 6.6.3.

How do I check if my server is vulnerable to CVE-2023-52764?

Run 'uname -r' and check if the output is between 6.6.0 and 6.6.2, then verify if CPIA1 driver is present with 'lsmod | grep gspca_cpia'. Both conditions must be true for vulnerability.

Does Defensia detect CVE-2023-52764?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2023-52764 will appear in your dashboard with remediation steps.

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References

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