CVE-2023-53436 – This CVE describes a memory leak vulnerability ... (How to Fix)

Q: What is the severity of CVE-2023-53436?

CVE-2023-53436 has a CVSS score of 5.5 (MEDIUM). This CVE describes a memory leak vulnerability in the Linux kernel's SNIC SCSI driver. If device_add() fails during device initialization, the driver doesn't properly clean up allocated resources, potentially leading to kernel memory exhaustion. This affects systems using the SNIC driver for Cisco UCS virtual interface cards.

📋 TL;DR

This CVE describes a memory leak vulnerability in the Linux kernel's SNIC SCSI driver. If device_add() fails during device initialization, the driver doesn't properly clean up allocated resources, potentially leading to kernel memory exhaustion. This affects systems using the SNIC driver for Cisco UCS virtual interface cards.

💻 Affected Systems

Products:

Linux kernel with SNIC driver enabled

Versions: Linux kernel versions before the fix commits (specific versions vary by distribution)

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if SNIC driver is loaded and used (typically for Cisco UCS virtual interface cards). Most systems don't have this driver loaded by default.

📦 What is this software?

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

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Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Sustained exploitation could lead to kernel memory exhaustion, causing system instability, crashes, or denial of service on affected systems.

🟠

Likely Case

Memory leak during device initialization failures, potentially causing gradual memory consumption and system performance degradation over time.

🟢

If Mitigated

Minor performance impact during rare device initialization failures with proper memory management.

🌐 Internet-Facing: LOW - Requires local access to trigger the vulnerability through device operations.

🏢 Internal Only: MEDIUM - Requires local access but could be exploited by authenticated users or through other local attack vectors.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access and ability to trigger device initialization failures. Not directly exploitable for privilege escalation.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Linux kernel with commits 41320b18a0e0, 461f8ac666fa, 58889d5ad74c, 7723a5d5d187, or 789275f7c054 applied

Vendor Advisory: https://git.kernel.org/stable/c/41320b18a0e0dfb236dba4edb9be12dba1878156

Restart Required: Yes

Instructions:

1. Update to a patched kernel version from your distribution vendor. 2. Reboot the system to load the new kernel. 3. Verify the SNIC driver is using the patched code.

🔧 Temporary Workarounds

Disable SNIC driver

all

Prevent loading of the vulnerable SNIC driver if not needed

echo 'blacklist snic' >> /etc/modprobe.d/blacklist.conf
rmmod snic

🧯 If You Can't Patch

Monitor system memory usage for unusual consumption patterns
Restrict local access to systems using SNIC driver to trusted users only

🔍 How to Verify

Check if Vulnerable:

Check if SNIC module is loaded: lsmod | grep snic. If loaded, check kernel version against patched versions.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes the fix commits or is from a distribution that has backported the patches.

📡 Detection & Monitoring

Log Indicators:

Kernel oops messages related to SNIC driver
System log entries showing memory allocation failures

Network Indicators:

None - this is a local vulnerability

SIEM Query:

Search for kernel panic logs or memory allocation failure messages in system logs

📊 Metadata

CVE ID: CVE-2023-53436

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-401

EPSS Score: 0.01% exploit probability (1.3th percentile)

Published: September 18, 2025

Last Updated: January 14, 2026

🔗 References

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