CVE-2024-56606
📋 TL;DR
A use-after-free vulnerability in the Linux kernel's af_packet subsystem allows attackers to potentially execute arbitrary code or cause denial of service. This affects Linux systems using the AF_PACKET socket interface, which is commonly used by packet sniffing tools and network monitoring applications. Attackers need local access to exploit this vulnerability.
💻 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 privilege escalation to kernel-level code execution, potentially leading to full system compromise, data theft, or persistent backdoor installation.
Likely Case
Kernel panic leading to system crash and denial of service, requiring system reboot to restore functionality.
If Mitigated
Limited impact due to proper access controls preventing unprivileged users from creating AF_PACKET sockets.
🎯 Exploit Status
Exploitation requires local access and understanding of kernel memory management. The use-after-free condition occurs when sock_init_data() fails after attaching sk object to sock object.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Multiple stable kernel versions with fixes referenced in git commits
Vendor Advisory: https://git.kernel.org/stable/c/132e615bb1d7cdec2d3cfbdec2efa630e923fd21
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Restrict AF_PACKET socket creation
linuxPrevent unprivileged users from creating AF_PACKET sockets using kernel capabilities or security modules
sysctl -w net.core.bpf_jit_enable=0
capsh --drop=cap_net_raw -- -c 'your_command'
Use SELinux/AppArmor restrictions
linuxConfigure mandatory access control to restrict AF_PACKET socket usage
setsebool -P deny_ptrace on
aa-disable /usr/sbin/tcpdump
🧯 If You Can't Patch
- Restrict user access to systems and monitor for privilege escalation attempts
- Implement strict capability management to prevent unprivileged users from obtaining CAP_NET_RAW
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with patched versions from distribution advisoriesCheck Version:
uname -rVerify Fix Applied:
Verify kernel version matches patched version and test AF_PACKET socket creation functionality📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages
- System crashes/reboots
- Failed AF_PACKET socket creation attempts in audit logs
Network Indicators:
- Unusual packet capture activity from non-privileged users
SIEM Query:
source="kernel" AND ("Oops" OR "general protection fault" OR "use-after-free")🔗 References
- https://git.kernel.org/stable/c/132e615bb1d7cdec2d3cfbdec2efa630e923fd21
- https://git.kernel.org/stable/c/157f08db94123e2ba56877dd0ac88908b13a5dd0
- https://git.kernel.org/stable/c/1dc1e1db927056cb323296e2294a855cd003dfe7
- https://git.kernel.org/stable/c/46f2a11cb82b657fd15bab1c47821b635e03838b
- https://git.kernel.org/stable/c/71b22837a5e55ac27d6a14b9cdf2326587405c4f
- https://git.kernel.org/stable/c/a6cf750b737374454a4e03a5ed449a3eb0c96414
- https://git.kernel.org/stable/c/fd09880b16d33aa5a7420578e01cd79148fa9829
- https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html
- https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html
