CVE-2022-49267
📋 TL;DR
This CVE describes a buffer overflow vulnerability in the Linux kernel's MMC core subsystem where sprintf() was used for sysfs output instead of the safer sysfs_emit(). This could allow local attackers to potentially execute arbitrary code or cause denial of service. Affected systems are those running vulnerable Linux kernel versions with MMC functionality.
💻 Affected Systems
- Linux kernel
📦 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...
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
Local privilege escalation to kernel-level code execution, potentially leading to full system compromise.
Likely Case
Kernel panic or system crash causing denial of service.
If Mitigated
Limited impact due to local-only access requirement and kernel hardening features like KASLR.
🎯 Exploit Status
Requires local access and knowledge of kernel exploitation techniques. No public exploits known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patched in kernel commits: 0f55ac683b2722714016f16daae9cab3f7f7b9f9, 659ca56b5415c7a1d05e185c36fad80ba165d063, c4ab65738ab3e21fe519ee46b2051222bc8e32ef, f5d8a5fe77ce933f53eb8f2e22bb7a1a2019ea11
Vendor Advisory: https://git.kernel.org/stable/c/0f55ac683b2722714016f16daae9cab3f7f7b9f9
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel.
🔧 Temporary Workarounds
Restrict sysfs access
allLimit access to MMC sysfs interfaces to reduce attack surface.
chmod 600 /sys/class/mmc_host/*
chown root:root /sys/class/mmc_host/*
🧯 If You Can't Patch
- Implement strict access controls to limit local user privileges
- Disable MMC functionality if not required for system operation
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with distribution's security advisories. Examine kernel source for sprintf() usage in mmc core sysfs code.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes the patched commits. Check that sysfs_emit() is used instead of sprintf() in mmc core sysfs handlers.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- System crash dumps
- Unexpected MMC-related errors
Network Indicators:
- None - local vulnerability only
SIEM Query:
Search for kernel panic events or privilege escalation attempts from local users