CVE-2024-27415

4.7 MEDIUM

Denial of Service

📋 TL;DR

A race condition vulnerability in the Linux kernel's netfilter bridge module allows multicast/broadcast packets to bypass conntrack confirmation, potentially causing packet processing issues. This affects Linux systems using bridge networking with netfilter rules, particularly those handling multicast traffic. The vulnerability can lead to NAT failures and conntrack helper malfunctions.

💻 Affected Systems

Products:

Linux kernel

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

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable when using bridge networking with netfilter rules that handle multicast/broadcast traffic. Systems without bridge networking or without netfilter rules for multicast are not affected.

📦 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 →

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

Network disruption where multicast packets fail to be properly NATed or processed by conntrack helpers, potentially causing service interruptions for multicast-dependent applications.

🟠

Likely Case

Intermittent packet processing issues for multicast traffic on bridged networks, with NAT and conntrack helpers being disabled for affected packets.

🟢

If Mitigated

Minimal impact if systems don't use bridge networking with netfilter rules handling multicast traffic.

🌐 Internet-Facing: LOW - This primarily affects internal network bridge configurations rather than direct internet-facing services.

🏢 Internal Only: MEDIUM - Affects internal network infrastructure using Linux bridge networking with netfilter rules.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires specific network conditions (bridge with multicast traffic) and would cause denial of service or packet processing issues rather than privilege escalation or remote code execution.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Patches available in stable kernel trees (commits: 2b1414d5e94e477edff1d2c79030f1d742625ea0, 62e7151ae3eb465e0ab52a20c941ff33bb6332e9, 7c3f28599652acf431a2211168de4a583f30b6d5, 80cd0487f630b5382734997c3e5e3003a77db315, cb734975b0ffa688ff6cc0eed463865bf07b6c01)

Vendor Advisory: https://git.kernel.org/stable/c/2b1414d5e94e477edff1d2c79030f1d742625ea0

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel. 3. Verify kernel version matches patched release.

🔧 Temporary Workarounds

Disable bridge netfilter for multicast

linux

Configure netfilter rules to bypass conntrack for multicast traffic on bridges

iptables -t raw -A PREROUTING -i br0 -m physdev --physdev-in ethX --physdev-out ethY -d 224.0.0.0/4 -j NOTRACK
iptables -t raw -A PREROUTING -i br0 -m physdev --physdev-in ethX --physdev-out ethY -d 255.255.255.255 -j NOTRACK

Disable bridge netfilter entirely

linux

Turn off netfilter bridge support if not required

echo 0 > /proc/sys/net/bridge/bridge-nf-call-iptables
echo 0 > /proc/sys/net/bridge/bridge-nf-call-ip6tables
echo 0 > /proc/sys/net/bridge/bridge-nf-call-arptables

🧯 If You Can't Patch

Implement workarounds to bypass conntrack for multicast traffic on bridges
Monitor network traffic for anomalies in multicast packet processing

🔍 How to Verify

Check if Vulnerable:

Check if system uses bridge networking with netfilter rules and handles multicast traffic. Review kernel version against patched releases.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes the fix commits and test multicast traffic processing on bridged interfaces.

📡 Detection & Monitoring

Log Indicators:

Kernel logs showing conntrack errors for multicast packets
Network monitoring showing multicast packet loss on bridges

Network Indicators:

Multicast traffic anomalies on bridged networks
NAT failures for multicast packets

SIEM Query:

source="kernel" AND ("conntrack" OR "nf_confirm") AND ("multicast" OR "broadcast")

📊 Metadata

CVE ID: CVE-2024-27415

CVSS v3 Score: 4.7 (MEDIUM)

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

CWE: CWE-362

Published: May 17, 2024

Last Updated: September 26, 2025

🔗 References