CVE-2023-53052
📋 TL;DR
This is a use-after-free vulnerability in the Linux kernel's CIFS (Common Internet File System) implementation, specifically in the DFS cache refresh worker. It allows attackers with local access to potentially execute arbitrary code or cause denial of service by exploiting memory corruption. Systems running vulnerable Linux kernel versions with CIFS/DFS enabled are affected.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Local privilege escalation to kernel-level code execution, potentially leading to complete system compromise.
Likely Case
Kernel panic or system crash causing denial of service.
If Mitigated
Limited to denial of service if exploit fails or system has additional protections like KASAN.
🎯 Exploit Status
Requires local access and specific CIFS/DFS configuration. The KASAN report suggests memory corruption is detectable.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions with commit 396935de145589c8bfe552fa03a5e38604071829 or later
Vendor Advisory: https://git.kernel.org/stable/c/396935de145589c8bfe552fa03a5e38604071829
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. For custom kernels, apply commit 396935de145589c8bfe552fa03a5e38604071829. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable CIFS DFS support
linuxPrevent use of DFS features in CIFS mounts to avoid triggering vulnerable code path.
mount -t cifs -o nodfs //server/share /mountpoint
Disable CIFS module
linuxUnload CIFS kernel module if not required.
rmmod cifs
🧯 If You Can't Patch
- Restrict local access to systems using CIFS/DFS mounts
- Monitor for kernel panics or KASAN reports related to CIFS/DFS operations
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if commit 396935de145589c8bfe552fa03a5e38604071829 is present. Also verify CIFS DFS usage.Check Version:
uname -rVerify Fix Applied:
Confirm kernel version includes the fix commit and test CIFS DFS operations without crashes.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- KASAN reports mentioning cifs or refresh_cache_worker
- System crashes during CIFS operations
Network Indicators:
- Unusual CIFS/DFS traffic patterns from local users
SIEM Query:
source="kernel" AND ("KASAN" OR "use-after-free" OR "cifs" OR "refresh_cache_worker")