CVE-2023-53661
📋 TL;DR
This CVE-2023-53661 is an integer overflow vulnerability in the bnxt_get_nvram_directory() function of the Linux kernel's Broadcom NetXtreme Ethernet driver. It could allow local attackers to cause denial of service or potentially execute arbitrary code by triggering memory corruption. Systems running affected Linux kernel versions with bnxt drivers loaded are vulnerable.
💻 Affected Systems
- Linux kernel with bnxt (Broadcom NetXtreme) Ethernet driver
📦 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 attempts are detected and contained.
🎯 Exploit Status
Requires local access and knowledge of driver internals. No public exploits known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel with commits 17e0453a7523ad7a25bb47af941b150a6c66d7b6, 7c6dddc239abe660598c49ec95ea0ed6399a4b2a, d5eaf2a6b077f32a477feb1e9e1c1f60605b460e, or efb1a257513438d43f4335f09b2f684e8167cad2 applied
Vendor Advisory: https://git.kernel.org/stable/c/17e0453a7523ad7a25bb47af941b150a6c66d7b6
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify bnxt driver is updated.
🔧 Temporary Workarounds
Disable bnxt driver
LinuxPrevent loading of vulnerable bnxt driver if not needed
echo 'blacklist bnxt_en' >> /etc/modprobe.d/blacklist-bnxt.conf
update-initramfs -u
reboot
🧯 If You Can't Patch
- Restrict local access to systems using mandatory access controls (SELinux/AppArmor)
- Implement strict privilege separation and limit user permissions
🔍 How to Verify
Check if Vulnerable:
Check if bnxt driver is loaded: lsmod | grep bnxt. Check kernel version against distribution security advisories.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits. Check dmesg for bnxt driver loading without errors.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- bnxt driver crash in dmesg
- System crash/reboot logs
Network Indicators:
- None - local exploitation only
SIEM Query:
Search for kernel panic events or unexpected system reboots on Linux hosts with bnxt driver