CVE-2023-53271
📋 TL;DR
This CVE describes a memory leak vulnerability in the Linux kernel's UBI (Unsorted Block Images) subsystem. When resizing UBI volumes, the kernel fails to properly free allocated memory, leading to gradual memory exhaustion over time. This affects any Linux system using UBI, particularly embedded devices and systems with flash storage.
💻 Affected Systems
- Linux kernel with UBI subsystem enabled
📦 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 →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 through resource depletion.
Likely Case
Gradual memory leak over time requiring periodic reboots to maintain system stability, particularly on systems that frequently resize UBI volumes.
If Mitigated
Minimal impact with proper monitoring and regular maintenance, though memory usage would still increase over time without patching.
🎯 Exploit Status
Exploitation requires ability to resize UBI volumes via ioctl calls, typically requiring appropriate privileges. The vulnerability is a resource exhaustion issue rather than a privilege escalation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel versions containing the fix commits (07b60f7452d2fa731737552937cb81821919f874 and related)
Vendor Advisory: https://git.kernel.org/stable/c/07b60f7452d2fa731737552937cb81821919f874
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. For embedded systems: Update kernel through vendor channels. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable UBI volume resizing
allPrevent users from resizing UBI volumes to avoid triggering the memory leak
chmod 000 /dev/ubi*
remove resize permissions from UBI device nodes
Monitor memory usage
allImplement monitoring to detect abnormal memory consumption and trigger alerts
Implement monitoring for /proc/meminfo or kernel memory statistics
🧯 If You Can't Patch
- Implement strict access controls to prevent unauthorized users from accessing UBI device nodes
- Schedule regular system reboots to clear accumulated memory leaks
🔍 How to Verify
Check if Vulnerable:
Check kernel version and verify if UBI subsystem is enabled: 'cat /proc/config.gz | gunzip | grep CONFIG_MTD_UBI' and 'uname -r'Check Version:
uname -rVerify Fix Applied:
Verify kernel version contains fix commits: 'uname -r' and check with distribution vendor for patched versions📡 Detection & Monitoring
Log Indicators:
- Kernel oom-killer messages
- System instability or crash reports
- Increasing memory usage in monitoring systems
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
Search for: 'Out of memory' OR 'kernel: Out of memory' OR 'oom-killer' in system logs🔗 References
- https://git.kernel.org/stable/c/07b60f7452d2fa731737552937cb81821919f874
- https://git.kernel.org/stable/c/09780a44093b53f9cbca76246af2e4ff0884e512
- https://git.kernel.org/stable/c/1e591ea072df7211f64542a09482b5f81cb3ad27
- https://git.kernel.org/stable/c/26ec2d66aecab8ff997b912c20247fedba4f5740
- https://git.kernel.org/stable/c/27b760b81951d8d5e5c952a696af8574052b0709
- https://git.kernel.org/stable/c/31d60afe2cc2b712dbefcaab6b7d6a47036f844e
- https://git.kernel.org/stable/c/5c0c81a313492b83bd0c038b8839b0e04eb87563
- https://git.kernel.org/stable/c/95a72417dd13ebcdcb1bd0c5d4d15f7c5bfbb288
