CVE-2024-57791

Q: What is the severity of CVE-2024-57791?

CVE-2024-57791 has a CVSS score of 7.5 (HIGH). A vulnerability in the Linux kernel's SMC (Shared Memory Communications) subsystem could cause a denial-of-service condition. When processing CLC (Connection Layer Control) messages, improper validation of network-supplied length values could lead to an infinite loop, potentially causing system hangs. This affects Linux systems using the SMC networking protocol.

7.5 HIGH

📋 TL;DR

A vulnerability in the Linux kernel's SMC (Shared Memory Communications) subsystem could cause a denial-of-service condition. When processing CLC (Connection Layer Control) messages, improper validation of network-supplied length values could lead to an infinite loop, potentially causing system hangs. This affects Linux systems using the SMC networking protocol.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected versions not explicitly stated in CVE, but patches are available in stable kernel trees

Operating Systems: Linux distributions using vulnerable kernel versions with SMC enabled

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if SMC protocol is enabled and in use. Many distributions don't enable SMC 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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⚠️ Risk & Real-World Impact

🔴

Worst Case

System becomes completely unresponsive requiring hard reboot, potentially affecting multiple services running on the same host.

🟠

Likely Case

Targeted SMC connections fail or cause temporary service disruption until the affected process is terminated.

🟢

If Mitigated

Minimal impact with proper network segmentation and SMC protocol restrictions.

🌐 Internet-Facing: LOW - SMC is typically used in internal/private networks, not internet-facing services.

🏢 Internal Only: MEDIUM - Internal attackers with network access to SMC ports could cause targeted DoS.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires ability to send specially crafted SMC CLC messages to vulnerable systems. Network access to SMC ports needed.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Patches available in stable kernel trees (commits referenced in CVE)

Vendor Advisory: https://git.kernel.org/stable/c/6b80924af6216277892d5f091f5bfc7d1265fa28

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from distribution vendor. 2. Reboot system to load new kernel. 3. Verify SMC functionality remains operational.

🔧 Temporary Workarounds

Disable SMC protocol

Linux

Disable the SMC networking protocol if not required

modprobe -r smc
echo 'blacklist smc' >> /etc/modprobe.d/blacklist.conf

🧯 If You Can't Patch

Implement network segmentation to restrict SMC traffic to trusted hosts only
Use firewall rules to block SMC protocol (port 5094 typically) from untrusted networks

🔍 How to Verify

Check if Vulnerable:

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

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes the patch commits referenced in CVE, or test SMC functionality with malformed packets.

📡 Detection & Monitoring

Log Indicators:

Kernel logs showing SMC connection issues
System becoming unresponsive with high CPU in kernel space

Network Indicators:

Unusual SMC protocol traffic patterns
Repeated connection attempts on SMC ports

SIEM Query:

source="kernel" AND ("smc" OR "SMC") AND ("error" OR "panic" OR "hang")

📊 Metadata

CVE ID: CVE-2024-57791

CVSS v3 Score: 7.5 (HIGH)

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

EPSS Score: 0.57% exploit probability (68.1th percentile)

Published: January 11, 2025

Last Updated: November 3, 2025

📋 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

⚠️ Risk & Real-World Impact

Worst Case

Likely Case

If Mitigated

🎯 Exploit Status

🛠️ Fix & Mitigation

✅ Official Fix

Instructions:

🔧 Temporary Workarounds

Disable SMC protocol

🧯 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