high CVSS 7.5 EPSS 0.28%

CVE-2023-52696·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: powerpc/powernv: Add a null pointer check in opal_powercap_init() kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure.

Severity
high
Software
Kernel
Fixed in
6.7.2
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 0.28% — higher than 51% 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-2023-52696 scores 7.5 on CVSS, so a successful attack would be serious — but at 0.28%, 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: 6.7

Until: 6.7.2

Fixed in: 6.7.2

How to fix this CVE

Update your Linux kernel to version 6.7.2 or later to patch a null pointer dereference vulnerability in the PowerNV power capping subsystem. Systems running kernel versions 6.7 through 6.7.1 on PowerPC architectures should prioritize this update to prevent potential denial of service conditions. Apply the patch through your distribution's standard kernel update mechanism.

sudo dnf update kernel kernel-headers kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check current kernel version: uname -r — Verify if version is between 6.7 and 6.7.1
  2. Confirm PowerNV platform: cat /proc/cpuinfo | grep -i power — Look for PowerPC or ppc64 indicators
  3. Check for opal_powercap module: lsmod | grep powercap — Determine if the vulnerable component is loaded
  4. Verify patch application: grep -i 'opal_powercap_init' /boot/config-$(uname -r) — Confirm kernel was compiled with POWERNV_POWERCAP enabled, then reboot and re-run uname -r to confirm 6.7.2 or later

FAQ

What is CVE-2023-52696?

This vulnerability is a null pointer dereference in the Linux kernel's PowerNV power capping initialization routine. When memory allocation fails during driver initialization, the code did not properly check for null pointers, potentially leading to a kernel panic or denial of service on PowerPC systems.

Is CVE-2023-52696 being actively exploited?

No, this vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog and no public exploits are known to exist. However, it remains a high-severity denial of service risk that should be remediated promptly.

What versions of Kernel are affected by CVE-2023-52696?

Linux kernel versions 6.7, 6.7.1, and 6.7.2 (prior to the patch) are affected. The vulnerability is specific to PowerNV (IBM Power Systems running Linux) platforms. Version 6.7.2 and later include the fix.

How do I check if my server is vulnerable to CVE-2023-52696?

Run uname -r to check your kernel version. If the output shows 6.7.0 or 6.7.1, and uname -m shows ppc64 or ppc64le, your system is vulnerable. Also verify that POWERNV_POWERCAP is enabled in your kernel configuration.

Does Defensia detect CVE-2023-52696?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2023-52696 will appear in your dashboard with remediation steps.

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References

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