CVE-2022-50243

Q: What is the severity of CVE-2022-50243?

CVE-2022-50243 has a CVSS score of 7.8 (HIGH). This is a use-after-free vulnerability in the Linux kernel's SCTP (Stream Control Transmission Protocol) implementation. When sctp_auth_asoc_init_active_key() fails, the system incorrectly frees an authentication key while it's still being used, potentially allowing attackers to crash systems or execute arbitrary code. This affects Linux systems with SCTP enabled.

7.8 HIGH

Denial of Service

📋 TL;DR

This is a use-after-free vulnerability in the Linux kernel's SCTP (Stream Control Transmission Protocol) implementation. When sctp_auth_asoc_init_active_key() fails, the system incorrectly frees an authentication key while it's still being used, potentially allowing attackers to crash systems or execute arbitrary code. This affects Linux systems with SCTP enabled.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected versions not specified in CVE, but patches exist for multiple stable branches

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if SCTP protocol support is compiled into the kernel and enabled. Many distributions disable SCTP 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

Remote code execution leading to full system compromise, denial of service, or privilege escalation to kernel level.

🟠

Likely Case

Kernel panic or system crash resulting in denial of service.

🟢

If Mitigated

No impact if SCTP is disabled or systems are patched.

🌐 Internet-Facing: MEDIUM - Requires SCTP to be enabled and accessible, which is less common than TCP/UDP.

🏢 Internal Only: LOW - SCTP is typically used in specialized applications rather than general networking.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Discovered via syzbot fuzzing. Exploitation requires sending specially crafted SCTP packets to trigger the use-after-free condition.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Multiple stable kernel versions with fixes available (see references)

Vendor Advisory: https://git.kernel.org/stable/c/022152aaebe116a25c39818a07e175a8cd3c1e11

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version. 2. Reboot system. 3. Verify kernel version after reboot.

🔧 Temporary Workarounds

Disable SCTP kernel module

linux

Prevent loading of SCTP kernel module to mitigate vulnerability

echo 'install sctp /bin/true' >> /etc/modprobe.d/disable-sctp.conf
rmmod sctp

Block SCTP traffic at firewall

linux

Prevent SCTP packets from reaching vulnerable systems

iptables -A INPUT -p sctp -j DROP
iptables -A OUTPUT -p sctp -j DROP

🧯 If You Can't Patch

Disable SCTP protocol support in kernel configuration
Implement network segmentation to isolate systems using SCTP

🔍 How to Verify

Check if Vulnerable:

Check if SCTP module is loaded: lsmod | grep sctp. If loaded and kernel is unpatched, system is vulnerable.

Check Version:

uname -r

Verify Fix Applied:

Check kernel version against patched versions and verify SCTP functionality works without crashes.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
System crashes
SCTP authentication errors in kernel logs

Network Indicators:

Unusual SCTP traffic patterns
SCTP packets with malformed authentication data

SIEM Query:

source="kernel" AND ("panic" OR "Oops" OR "use-after-free") AND "sctp"

📊 Metadata

CVE ID: CVE-2022-50243

CVSS v3 Score: 7.8 (HIGH)

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

CWE: CWE-416

EPSS Score: 0.01% exploit probability (1.2th percentile)

Published: September 15, 2025

Last Updated: November 24, 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

Linux Kernel by Linux

⚠️ Risk & Real-World Impact

Worst Case

Likely Case

If Mitigated

🎯 Exploit Status

🛠️ Fix & Mitigation

✅ Official Fix

Instructions:

🔧 Temporary Workarounds

Disable SCTP kernel module

Block SCTP traffic at firewall

🧯 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

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