medium CVSS 5.5 EPSS <0.1%

CVE-2023-52763·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: i3c: master: mipi-i3c-hci: Fix a kernel panic for accessing DAT_data. The `i3c_master_bus_init` function may attach the I2C devices before the I3C bus initialization. In this flow, the DAT `alloc_entry`` will be used before the DAT `init`. Additionally, if the `i3c_master_bus_init` fails, the DAT `cleanup` will execute before the device is detached, which will execue DAT `free_entry` function. The above scenario can cause the driver to use DAT_data when it is NULL.

Severity
medium
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 <0.1% — 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.

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 resolve a critical null pointer dereference in the MIPI I3C HCI master driver. This vulnerability occurs when I2C device attachment happens during I3C bus initialization before the Device Address Table (DAT) is properly initialized, or when cleanup operations occur in the wrong order during initialization failures. Affected systems running kernel versions 6.6 through 6.6.2 should prioritize this update to prevent kernel panics.

sudo dnf update kernel kernel-devel && sudo reboot

Defensia detects this vulnerability

How to check if you are affected

  1. Check current kernel version: uname -r (should be 6.6.3 or higher; vulnerable if output shows 6.6.0, 6.6.1, or 6.6.2)
  2. Verify MIPI I3C HCI master driver is loaded: lsmod | grep i3c (confirms the vulnerable component is active)
  3. Search kernel logs for panic signatures: sudo dmesg | grep -i 'kernel panic\|NULL pointer\|i3c.*master' (look for BUG or OOPS messages)
  4. After patching, confirm kernel version: uname -r (should display 6.6.3 or later)

FAQ

What is CVE-2023-52763?

This vulnerability is a null pointer dereference in the Linux kernel's MIPI I3C HCI master driver that triggers a kernel panic. It occurs due to improper ordering of Device Address Table (DAT) initialization and I2C device attachment, allowing the driver to reference uninitialized memory.

Is CVE-2023-52763 being actively exploited?

No, this vulnerability is not listed in CISA's Known Exploited Vulnerabilities catalog and no public exploits are available. However, it can be easily triggered by local code with privilege escalation capability.

What versions of Kernel are affected by CVE-2023-52763?

Linux kernel versions 6.6.0, 6.6.1, and 6.6.2 are vulnerable. The fix is available in kernel 6.6.3 and all subsequent releases.

How do I check if my server is vulnerable to CVE-2023-52763?

Run 'uname -r' and check if the output is between 6.6.0 and 6.6.2. Additionally, verify the MIPI I3C driver is loaded with 'lsmod | grep i3c'. If both conditions are true, your system is vulnerable.

Does Defensia detect CVE-2023-52763?

Yes — Defensia's CVE advisory scanner compares installed kernel versions against the NVD database. If a vulnerable kernel version is detected on a monitored server, CVE-2023-52763 will appear in your dashboard with remediation steps and affected package details.

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References

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