high CVSS 7.8 EPSS 0.13%

CVE-2023-52667·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: fix a potential double-free in fs_any_create_groups When kcalloc() for ft->g succeeds but kvzalloc() for in fails, fs_any_create_groups() will free ft->g. However, its caller fs_any_create_table() will free ft->g again through calling mlx5e_destroy_flow_table(), which will lead to a double-free. Fix this by setting ft->g to NULL in fs_any_create_groups().

Severity
high
Software
Kernel
Fixed in
6.7.3
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 0.13% — higher than 33% 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-2023-52667 scores 7.8 on CVSS, so a successful attack would be serious — but at 0.13%, 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: 6.7.3

Fixed in: 6.7.3

How to fix this CVE

Update your Linux kernel to version 6.7.3 or later to resolve a memory management flaw in the MLX5 Ethernet driver's flow table creation logic. This vulnerability allows local attackers to trigger a double-free condition that could crash the system or potentially execute code with kernel privileges. Prioritize this update for systems running kernel versions 6.7 through 6.7.2.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check your current kernel version: uname -r — if it shows 6.7.0, 6.7.1, or 6.7.2, your system is vulnerable.
  2. Verify MLX5 driver is loaded: lsmod | grep mlx5 — if no output, this vulnerability has no impact on your system.
  3. Search kernel logs for memory allocation failures in flow table setup: sudo dmesg | grep -i 'mlx5\|kvzalloc\|kcalloc' — look for error messages occurring during network device initialization.
  4. After patching, confirm kernel version: uname -r — should show 6.7.3 or later, and verify driver reloaded: sudo modprobe -r mlx5_core && sudo modprobe mlx5_core.

FAQ

What is CVE-2023-52667?

This is a double-free vulnerability in the Linux kernel's MLX5 Ethernet driver flow table initialization. When memory allocation partially fails during flow group creation, the error handler frees memory that is subsequently freed again by the calling function, potentially leading to kernel crash or privilege escalation.

Is CVE-2023-52667 being actively exploited?

No, this vulnerability is not listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are available. However, it remains a high-severity local privilege escalation risk.

What versions of Kernel are affected by CVE-2023-52667?

Linux kernel versions 6.7, 6.7.1, and 6.7.2 are vulnerable. Kernel 6.7.3 and later versions contain the fix.

How do I check if my server is vulnerable to CVE-2023-52667?

Run 'uname -r' to check your kernel version; if it returns 6.7.0, 6.7.1, or 6.7.2 and 'lsmod | grep mlx5' shows the driver is loaded, your system is vulnerable.

Does Defensia detect CVE-2023-52667?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If the Linux kernel is installed on a monitored server, CVE-2023-52667 will appear in your dashboard with remediation steps.

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References

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