CVE-2023-1829
📋 TL;DR
CVE-2023-1829 is a use-after-free vulnerability in the Linux kernel's traffic control index filter (tcindex) that allows local attackers to escalate privileges to root. The flaw occurs when the tcindex_delete function fails to properly deactivate filters during deletion, leading to double-free conditions. This affects Linux systems with the tcindex module loaded.
💻 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 →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 attacker gains full root privileges, enabling complete system compromise, data theft, persistence, and lateral movement.
Likely Case
Local user escalates to root and installs backdoors, modifies system configurations, or accesses sensitive data.
If Mitigated
With proper access controls and unprivileged user restrictions, impact is limited to denial-of-service or local resource exhaustion.
🎯 Exploit Status
Exploitation requires local access and knowledge of kernel exploitation techniques. Proof-of-concept code has been published.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions including commit 8c710f75256bb3cf05ac7b1672c82b92c43f3d28
Vendor Advisory: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8c710f75256bb3cf05ac7b1672c82b92c43f3d28
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing fix commit 8c710f75256bb3cf05ac7b1672c82b92c43f3d28. 2. Reboot system to load patched kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Unload tcindex module
linuxPrevent exploitation by unloading the vulnerable tcindex kernel module
rmmod tcindex
Blacklist tcindex module
linuxPrevent tcindex module from loading at boot
echo 'blacklist tcindex' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Restrict local user access and implement least privilege principles
- Monitor for privilege escalation attempts and unusual root activity
🔍 How to Verify
Check if Vulnerable:
Check if tcindex module is loaded: lsmod | grep tcindex. Check kernel version against patched versions.Check Version:
uname -rVerify Fix Applied:
Verify kernel includes fix commit: git log --oneline | grep 8c710f75256bb3cf05ac7b1672c82b92c43f3d28 or check kernel version is after fix date.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- System crash dumps
- Unusual privilege escalation in audit logs
Network Indicators:
- None - local exploitation only
SIEM Query:
source="kernel" AND ("panic" OR "Oops" OR "general protection fault") OR source="audit" AND "privilege-escalation"🔗 References
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8c710f75256bb3cf05ac7b1672c82b92c43f3d28
- https://kernel.dance/#8c710f75256bb3cf05ac7b1672c82b92c43f3d28
- https://lists.debian.org/debian-lts-announce/2023/05/msg00005.html
- https://lists.debian.org/debian-lts-announce/2023/05/msg00006.html
- https://security.netapp.com/advisory/ntap-20230601-0001/
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8c710f75256bb3cf05ac7b1672c82b92c43f3d28
- https://kernel.dance/#8c710f75256bb3cf05ac7b1672c82b92c43f3d28
- https://lists.debian.org/debian-lts-announce/2023/05/msg00005.html
- https://lists.debian.org/debian-lts-announce/2023/05/msg00006.html
- https://security.netapp.com/advisory/ntap-20230601-0001/
