CVE-2023-53516
📋 TL;DR
A missing length validation in the Linux kernel's macvlan driver allows attackers to trigger a heap out-of-bounds read by providing malformed network link attributes. This affects Linux systems using macvlan interfaces, potentially leading to kernel crashes or information disclosure.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash, potential information disclosure from kernel memory, or local privilege escalation if combined with other vulnerabilities.
Likely Case
Kernel crash causing denial of service on affected systems, potentially requiring system reboot.
If Mitigated
Minimal impact with proper access controls preventing unprivileged users from creating/modifying macvlan interfaces.
🎯 Exploit Status
Requires CAP_NET_ADMIN capability to create/modify macvlan interfaces. Similar to CVE-2023-3773 exploitation patterns.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel with commit 55cef78c244d0d076f5a75a35530ca63c92f4426 or later
Vendor Advisory: https://git.kernel.org/stable/c/55cef78c244d0d076f5a75a35530ca63c92f4426
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify kernel version with 'uname -r'.
🔧 Temporary Workarounds
Restrict macvlan interface creation
linuxLimit CAP_NET_ADMIN capabilities to prevent unauthorized users from creating macvlan interfaces
# Use Linux capabilities to restrict CAP_NET_ADMIN
# Example: setcap -r /path/to/application
# Or use SELinux/AppArmor policies
Disable macvlan module
linuxPrevent loading of macvlan kernel module if not required
echo 'install macvlan /bin/false' >> /etc/modprobe.d/disable-macvlan.conf
rmmod macvlan
🧯 If You Can't Patch
- Restrict user access to prevent unauthorized users from having CAP_NET_ADMIN capabilities
- Implement strict network namespace isolation to limit blast radius
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if between vulnerable commits: 'uname -r' and verify with distribution security advisoriesCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes commit 55cef78c244d0d076f5a75a35530ca63c92f4426: 'grep -q 55cef78c244d0d076f5a75a35530ca63c92f4426 /proc/version'📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- OOM killer activity related to network interfaces
- Unexpected macvlan interface creation
Network Indicators:
- Unusual macvlan interface creation patterns
- Network namespace manipulation
SIEM Query:
source="kernel" AND ("panic" OR "Oops" OR "general protection fault") AND ("macvlan" OR "IFLA_MACVLAN")