CVE-2023-53004
📋 TL;DR
A memory leak vulnerability in the Linux kernel's OverlayFS (ovl) module when creating temporary files. This allows local attackers to cause resource exhaustion by repeatedly triggering the vulnerable code path. Affects Linux systems using OverlayFS with unpatched kernel versions.
💻 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 →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
Local attacker could exhaust kernel memory, leading to system instability, denial of service, or potential privilege escalation through memory corruption side effects.
Likely Case
Local user causes gradual memory consumption, potentially leading to system slowdowns or crashes requiring reboot.
If Mitigated
Minimal impact with proper memory limits and monitoring; isolated containers limit blast radius.
🎯 Exploit Status
Exploitation requires local access; no authentication bypass needed beyond local user privileges.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits baabaa505563362b71f2637aedd7b807d270656c and caa0ea92503f8afa1941f6ac899e5c4e3f6ec8bb
Vendor Advisory: https://git.kernel.org/stable/c/baabaa505563362b71f2637aedd7b807d270656c
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. For RHEL/CentOS: yum update kernel. 3. For Ubuntu/Debian: apt update && apt upgrade linux-image. 4. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable OverlayFS
linuxPrevent use of OverlayFS filesystem if not required
modprobe -r overlay
echo 'blacklist overlay' >> /etc/modprobe.d/blacklist.conf
Limit memory per user
linuxSet memory limits to contain potential exhaustion
ulimit -v [LIMIT]
Edit /etc/security/limits.conf with 'hard as [LIMIT]'
🧯 If You Can't Patch
- Restrict local user access to systems using OverlayFS
- Monitor kernel memory usage and implement alerts for abnormal consumption
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if OverlayFS module is loaded: lsmod | grep overlay && uname -rCheck Version:
uname -rVerify Fix Applied:
Verify kernel version is after fix commits; check with distribution-specific patch tracking📡 Detection & Monitoring
Log Indicators:
- Kernel oom-killer messages
- Memory exhaustion warnings in dmesg
- High slab memory usage in /proc/meminfo
Network Indicators:
- None - local exploit only
SIEM Query:
source="dmesg" AND ("out of memory" OR "slab allocation failure")