Medium

Linux Kernel IPv6 Raw Socket NULL Pointer Dereference

IdentifiersCVE-2023-0394CWE-476· NULL Pointer Dereference

CVE-2023-0394 is a NULL pointer dereference in the Linux kernel IPv6 raw-socket transmit path, within rawv6_push_pending_frames. The function incorrectly treats the socket cork base length, which includes IPv6 extension-header bytes, as though it consisted solely of valid data in the cork queue. When an offset is greater than the queued data length but remains within the combined data and extension-header length, no socket buffer is selected. A subsequently NULL socket-buffer pointer is passed to skb_transport_offset, causing a kernel NULL pointer dereference.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful triggering crashes the Linux kernel, causing a system-wide denial of service. Available severity assessments assign high availability impact and no confidentiality or integrity impact.

Mitigation

If you can’t patch tonight, do this now.

No mitigation meeting Red Hat's criteria for usability, broad applicability, and stability was identified. Where patching cannot be performed immediately, restrict untrusted users' ability to create or manipulate raw IPv6 sockets and reduce exposure to untrusted local or adjacent-network users, recognizing that these measures are compensating controls rather than a vendor-supported fix.

Remediation

Patch, then assume compromise.

Install a kernel update containing the upstream fix and reboot to run the updated kernel. Red Hat fixes include RHEL 9 kernel updates released through RHSA-2023:2458, RHEL 9 real-time kernel updates through RHSA-2023:2148, RHEL 8 kernel updates through RHSA-2023:2951, RHEL 8 real-time kernel updates through RHSA-2023:2736, and applicable RHEL 8.6 EUS and Red Hat Virtualization updates through RHSA-2024:0412. Vendor kernels may backport the fix without adopting a newer upstream version, so package advisory status should be used rather than version-only scanning.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

LinuxLinux Kerneloperating_system

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

8 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

8 SOURCESView more in app

redhat accessNews

Jan 1, 2026

RHSA-2023:2148 - Security Advisory - Red Hat Customer Portal

Linux IPv6 raw-socket NULL-pointer dereference.

redhat accessNews

Jan 1, 2026

RHSA-2024:0412 - Security Advisory - Red Hat Customer Portal

Linux kernel NULL-pointer dereference in rawv6_push_pending_frames.

redhat accessNews

Jan 1, 2026

RHSA-2023:2458 - Security Advisory - Red Hat Customer Portal

Linux kernel IPv6 raw-socket NULL-pointer dereference vulnerability.

redhat accessNews

Jan 1, 2026

RHSA-2023:2951 - Security Advisory - Red Hat Customer Portal

Linux kernel IPv6 raw-socket NULL-pointer dereference.

+3 more in the timeline

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity