CVE-2024-53179
📋 TL;DR
A race condition in the Linux kernel's SMB client can cause a use-after-free vulnerability in the signing key during SMB2.1+ sign mounts. This allows attackers with network access to potentially crash the kernel or execute arbitrary code. Affects Linux systems using SMB client with signing enabled.
💻 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
Kernel panic leading to system crash or potential arbitrary code execution with kernel privileges, resulting in complete system compromise.
Likely Case
System instability, kernel crashes, or denial of service affecting SMB client operations.
If Mitigated
Limited to denial of service if exploit fails to achieve code execution, with potential system instability.
🎯 Exploit Status
Exploitation requires triggering a specific race condition during SMB operations with signing enabled. No public exploit code known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in stable kernel commits: 0e2b654a3848bf9da3b0d54c1ccf3f1b8c635591, 343d7fe6df9e247671440a932b6a73af4fa86d95, 39619c65ab4bbb3e78c818f537687653e112764d
Vendor Advisory: https://git.kernel.org/stable/c/0e2b654a3848bf9da3b0d54c1ccf3f1b8c635591
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version. 2. Check with your distribution vendor for specific kernel updates. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Disable SMB signing
linuxDisable SMB signing on client mounts to avoid triggering the vulnerable code path
mount -t cifs //server/share /mnt -o noserverino,nosharesock,vers=3.0,sec=ntlmssp
Use SMB3 without signing
linuxUse SMB3 protocol version without signing enabled
mount -t cifs //server/share /mnt -o vers=3.0
🧯 If You Can't Patch
- Disable SMB client signing on all mounts
- Restrict network access to SMB shares to trusted sources only
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if SMB signing is enabled on mounts. Use: mount | grep cifs and check for 'sec=' optionsCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commits or is newer than patched versions. Check with: uname -r and compare with distribution security advisories📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- SMB client connection failures
- Use-after-free kernel messages in dmesg
Network Indicators:
- Multiple rapid SMB connection attempts with signing enabled
- Abnormal SMB protocol traffic patterns
SIEM Query:
source="kernel" AND ("use-after-free" OR "UAF" OR "smb" OR "cifs")