CVE-2023-52919

Q: What is the severity of CVE-2023-52919?

CVE-2023-52919 has a CVSS score of 5.5 (MEDIUM). A NULL pointer dereference vulnerability exists in the Linux kernel's NFC (Near Field Communication) subsystem. If memory allocation fails in the send_acknowledge() function, an uninitialized pointer could be dereferenced, causing a kernel panic or system crash. This affects systems with NFC hardware and the nci module loaded.

5.5 MEDIUM

📋 TL;DR

A NULL pointer dereference vulnerability exists in the Linux kernel's NFC (Near Field Communication) subsystem. If memory allocation fails in the send_acknowledge() function, an uninitialized pointer could be dereferenced, causing a kernel panic or system crash. This affects systems with NFC hardware and the nci module loaded.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected versions not explicitly stated in CVE; check kernel commits for exact ranges

Operating Systems: Linux distributions with vulnerable kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if NFC hardware is present and nci module is loaded; many servers and systems without NFC are unaffected.

📦 What is this software?

Linux Kernel by Linux

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⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash and denial of service, potentially disrupting critical services on affected devices.

🟠

Likely Case

System crash or instability when NFC operations encounter memory pressure, requiring reboot to restore functionality.

🟢

If Mitigated

Minimal impact if NFC is disabled or the nci module isn't loaded; system continues normal operation.

🌐 Internet-Facing: LOW - Requires local access to NFC hardware and specific conditions; not directly exploitable over network.

🏢 Internal Only: MEDIUM - Affects devices with NFC hardware in enterprise environments; could cause service disruption if exploited.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access to trigger memory allocation failure in specific NFC operations; not trivial to exploit reliably.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Check kernel commits: 2b2edf089df3a69f0072c6e71563394c5a94e62e and others listed

Vendor Advisory: https://git.kernel.org/stable/c/2b2edf089df3a69f0072c6e71563394c5a94e62e

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution. 2. Reboot system to load new kernel. 3. Verify nci module loads without errors.

🔧 Temporary Workarounds

Disable NFC module

linux

Prevent loading of the vulnerable nci module if NFC is not needed

echo 'blacklist nci' >> /etc/modprobe.d/blacklist-nci.conf
rmmod nci

🧯 If You Can't Patch

Ensure NFC hardware is disabled in BIOS/UEFI if not required
Monitor system logs for kernel panic events related to NFC operations

🔍 How to Verify

Check if Vulnerable:

Check if nci module is loaded: lsmod | grep nci. If loaded and kernel version is unpatched, system may be vulnerable.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commits: uname -r and check against patched versions. Test NFC functionality if required.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages in /var/log/kern.log or dmesg
NULL pointer dereference errors mentioning nci or send_acknowledge

Network Indicators:

None - this is a local kernel vulnerability

SIEM Query:

source="kernel" AND ("NULL pointer dereference" OR "kernel panic") AND ("nci" OR "send_acknowledge")

📊 Metadata

CVE ID: CVE-2023-52919

CVSS v3 Score: 5.5 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-476

Published: October 22, 2024

Last Updated: October 24, 2024

📋 TL;DR

💻 Affected Systems

📦 What is this software?

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

⚠️ Risk & Real-World Impact

Worst Case

Likely Case

If Mitigated

🎯 Exploit Status

🛠️ Fix & Mitigation

✅ Official Fix

Instructions:

🔧 Temporary Workarounds

Disable NFC module

🧯 If You Can't Patch

🔍 How to Verify

Check if Vulnerable:

Check Version:

Verify Fix Applied:

📡 Detection & Monitoring

Log Indicators:

Network Indicators:

SIEM Query:

📊 Metadata

🔗 References

📤 Share & Export

🔗 Related Vulnerabilities